Structure of the Nervous System PDF
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Sabrina Bautista
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This document outlines the structure of the nervous system, including the central and peripheral nervous systems, basic features, and anatomical directions. It describes the brain's components, its blood supply, and protective structures, providing an overview of physiological psychology, suitable for undergraduate-level study.
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Structure of the Nervous System (Chapter 3) Physiological Psychology | Sabrina Bautista Anatomical Directions OUTLINE: ➔ A...
Structure of the Nervous System (Chapter 3) Physiological Psychology | Sabrina Bautista Anatomical Directions OUTLINE: ➔ A tonomists named most brain structures I. Basic Features of the Nervous System according to how similar they resembled objects' II. Structure and Function of the CNS III. Studying the Living Human Brain amygdala almond-shaped object IV. Structure and Function of the PNS hippocampus sea horse Basic Features of the Nervous System genu knee Division of the Nervous System cortex tree bark The nervous system is divided into 2 main parts: ➔ The Central Nervous System pons bridge ◆ Brain & spinal cord ➔ The Peripheral Nervous System uncus hook ◆ Cranial nerves, spinal nerves, and peripheral ganglia Protection of the CNS Neuraxis Imaginary line drawn through the length of the = ➔ B rain= protected by the skull central nervous system ➔ Spinal Cord= protected in the spine ➔ from the bottom of the spinal cord to the (vertebral column) front of the brain Make-up of Brain ➔ M ade up of neurons, glia, and other supporting cells ➔ Floats in cerebrospinal fluid (CSF) Brain & its Blood Supply ➔ T he brain receives about 20% of blood flow from the heart ➔ The brain gets a consistent blood supply ➔ The blood-brain barrier protects the brain from chemicals ➔ Glucose is crucial for the brain but it has limited storage for it which is why continuous blood flow is crucial ➔ Interrupted blood flow to the brain depletes its oxygen supply ➔ It takes a 6-second interruption to cause unconsciousness ➔ Several minutes without blood leads to permanent brain damage 1 ANTERIOR Toward the head Cross Section /Frontal Section POSTERIOR Toward the tail Cut from a persons side view (coronal plane) ROSTRAL Toward the front of the face CAUDAL Away from the front of the face DORSAL Top & Back of head VENTRAL ottom of the skull/ front of the B body LATERAL Toward the side MEDIAL Toward the Middle Horizontal sections Ipsilateral Contralateral Cut horizontally (axial) tructures on the S tructures on the S same side of the body opposite side of the body Sagittal Sections Cut from the Middle Down (midsaggital plane = cut right down the middle) Anatomical Planes ➔ The nervous system is sliced in 3 ways ◆ Cross sections ◆ Horizontal sections ◆ Saggittal Sections 2 SUMMARY orsal Vs D Ventral ostral Vs R Caudal he Meninges and the Ventricular System T Meninges protective sheets around the brain and spinal = cord ← meninges = membrane in Greek nterior vs A ➔ Consists of 3 layers posterior 1. Dura Mater 2. Arachnoid membrane uperior vs S 3. Pia Mater inferior Meninges Layers Dura Mater durable, thick, tough = but un-stretchable OUTTER layer edial vs M lateral rachnoid A weblike, soft and = Membrane spongey MIDDLE LAYER “arcane”= spider **Subarachnoid space = gap between the arachnoid membrane and pia matter oronal vs C sagittal Pia Mater attached to the brain = and spinal cord ontains smaller blood c vessels of the brain and spinal cord orizontal vs H Horizontal = Transverse Plane “Pious mother” transverse Ipsilateral vs Contralateral ➔ P NS is covered with 2 layers of meninges ➔ Acharoid membrane only covers the brain and spinal cord → pool of CSF 3 ➔ T he dura mater and pia mater fuse and form a sheath that covers the spinal nerves, cranial, nerves, and peripheral PROCESS: ganglia outside the CNS Ventricular system ➔ C onsists of ventricles = a series of hollow, interconnected chambers called ventricles ➔ (“little bellies”) ➔ Produce and are filled withCSF (cerebrospinal fluid) ➔ Types of ventricles ateral L 2 largest ventricles = Ventricles connected to the third ventricles FS is produced in the lateral ventricles C hird T located at the midline of the = → thru the cerebral aqueduct → to the fourth Ventricles brain → divides the vesicle where more CSF is produced → CFS surrounding parts of the brain leaves the fourth ventricle thru small openings into symmetrical halves connecting with the subarachnoid space (around the CNS) = CFS is reabsorbed into the blood assa Intermedia= bridge of M supply through the arachnoid granulations. neural tissues that crosses thru the middle of the third ventrical The Brain and CFS erebral C long tube connecting the third = Aqueduct ventricle to the fourth ➔ T he brain is very soft and jelly-like, which makes it fragile. ourth F ➔ It has a considerable weight of Ventricle approximately 1400 grams, which, along with its delicate structure, requires C FS = composed of chloroid plexus protection from physical shock. Chloroid plexus= special tissue rich in ➔ The brain is well-protected within the blood supply → extends into all 4 human body. ventricles ➔ It is suspended in cerebrospinal fluid Flow of CFS (CSF), which surrounds it in the subarachnoid space. ➔ This immersion in CSF reduces the brain's effective weight from 1400 g to around 80 g, thus: ◆ Relieving pressure on the base of the brain. ◆ Helping to cushion the brain against shock, especially from sudden head movements. 4 ➔ In the abdomen, the CSF is reabsorbed Obstructive Hydrocephalus into the bloodstream, thus regulating pressure and preventing further complications. SF flows through a specific route around the C brain and spinal cord (see section above) ➔ T his fluid continuously circulates to Structure & Function of the CNS maintain pressure balance and cushioning for the central nervous system (CNS). Interruption of CSF Flow: ➔ Causes of Blockage: ◆ Tumors in areas like the midbrain may press on structures such as thecerebral aqueduct, blocking CSF flow. ◆ Congenital issues, such as a small cerebral aqueduct, may restrict CSF movement from birth. ➔ Consequences of Blockage: ◆ When the flow of CSF is blocked, Major Ventricle Subdivision Principle the ventricles (fluid-filled cavities Division Structures within the brain) experience increased pressure. Forebrain Lateral Telencephalon Cerebral Cortex ◆ Thechoroid plexus, which Basal Ganglia produces CSF, continues to generate fluid despite the Limbic system blockage, causing the ventricles to Thalamus Third Diencephalon expand. ◆ This condition, calledobstructive Hypothalamus hydrocephalus(literally ectum T Midbrain Cerebral Mesecephalon "water-head"), can lead to severe queduct a Tegmentum complications: ◆ Increased intracerebral pressure Hindbrain Fourth Metecephalon Cerebellum may result in: Pons Occlusion (blocking) of blood vessels. Myelenecephalon Medulla Permanent or fatal brain damage if untreated. Treatment of Obstructive Hydrocephalus: ➔ S urgeons can relieve pressure by drilling a hole in the skull and inserting ashunt tubeinto one of the brain’s ventricles. ➔ The shunt tube is connected to a pressure relief valveimplanted in the abdominal cavity. ➔ When the pressure in the ventricles rises too high, the valve opens, allowing CSF to drain into the abdomen. 5 THE FOREBRAIN OVERVIEW ◆ W hite matter: Myelinated axons beneath the cortex, connecting Subdivision Components Function different regions. Telecephalon C erebral omplex C cortex functions: perception, Limbic memory, System emotion, and movement Basal Ganglia control Diecephalon he Forebrain: Telencephalon T Telecephalon Structures Structure Description Components Primary Functions Lobes of the Cerebral Cortex: erebral C uter layer, O rontal, F ensory S Cortex surrounds cerebral parietal, processing, Lobe Location Primary Function hemispheres; temporal, perception, folded with sulci, occipital motor control Frontal Lobe ront of the F ovement, M fissures, and gyri. lobes brain, anterior planning, to the central decision-making, imbic L ocated around L ingulate C motion, E sulcus motor control System medial edge of gyrus, memory, cerebral hippocampu learning hemispheres. s, amygdala, Parietal Lobe B ehind the omatosensory S fornix central sulcus, processing, dorsal region spatial orientation asal B ollection of nuclei C audate C ovement M Ganglia below the cortex in nucleus, control emporal T entral to the V uditory A the forebrain. putamen, globus Lobe frontal and processing, pallidus parietal lobes language, memory Cerebral Cortex ccipital O t the back of Visual processing A Lobe the brain Structure and Composition: ➔ T he cerebral cortex surrounds the cerebral hemispheres like tree bark. ➔ Convoluted with grooves (sulci), large grooves (fissures), and bulges (gyri) to increase surface area. ◆ Helps enlarge the area of the cortex compared to a smooth brain of the same size ◆ Tripples the area of the cerebral cortex ◆ Lissencephaly = smooth brain ➔ Approximately 2360 cm² in surface area and 3 mm thick. ➔ Composed mainly of: ◆ Gray matter: Cell bodies and dendrites (outer layer). 6 Primary Sensory Cortex: Lateralization in the Cerebral Cortex ○ T his area receives raw sensory input from Some functions of cerebral hemispheres are = different sensory organs, each type of lateralized—have functional specialization located sensory information being processed in its primarily on one side of the brain specific cortical area: Left hemisphere analyzes information Primary Visual Cortex: Located in Right hemisphere synthesizes information theoccipital lobealong the calcarine fissure; it receives input directly from the eyes and is essential for visual perception. Primary Auditory Cortex: Located in thetemporal lobenear thelateral fissure;it processes sound waves from the ears. Primary Somatosensory Cortex: Located in theparietal lobejust behind thecentral sulcus; it processes tactile, pain, and temperature sensations from the body. * **Insular cortex& primary somatory cortex Corpus callosum receive info on taste = a large band of axons Sensory Association Cortex: ➔ c onnects corresponding parts of the ➔ R eceives information from each primary cerebral cortex of the left and right sensory area hemispheres ➔ Circuits of neurons analyze received ➔ Split Brain:a condition where it is information surgically severed ← normally epilepsy ➔ Perception takes place and memories are stored ➔ Regions close to primary sensory areas receive ➔ information from only one sensory system Motor Cortex ➔ M ost directly involved in the control of movement ➔ neurons are connected (contralateral) to muscles in different parts of the body Motor Association Cortex ➔ R egion of frontal lobe rostral to primary motor cortex ➔ Also known as premotor cortex ➔ Involved in the planning and execution of movements 7 Limbic System Basal Ganglia a group of nuclei located deep within the = a group of interconnected structures on the = telencephalon, near the lateral ventricles. They medial side of each hemisphere, involved in are involved in motor control, procedural learning, emotional processing, learning, and memory. and various cognitive and emotional functions. Components: Brain Part Location Primary Function ingulate C bove the a rocessing emotions, P ➔ C audate Nucleus: An elongated nucleus Gyrus corpus pain perception, and that curves around the lateral ventricles; callosum regulating aggressive associated with motor processes, behavior. learning, and goal-directed behavior. Hippocampus ithin the w ritical for the C temporal lobe formation of new “Nucleous with a tail” memories and spatial djacent to the a navigation. ➔ P utamen: Lies adjacent to the caudate lateral ventricle nucleus; involved in motor skills and Amygdala lmond-shape A rocessing emotions, P reinforcement learning. d cluster of particularly fear and nuclei situated aggression, and is “shell” in the temporal involved in storing lobe, near the emotional memories. ➔ G lobus Pallidus: Located next to the hippocampus putamen; plays a role in controlling Fornix bundle of A ssential for the E voluntary movement and regulating nerve fibers limbic system's inhibitory motor control. connecting the memory circuits. hippocampus “Pale globe” to other parts of the limbic system, including the hypothalamus ammillary M ound R Involved in Bodies structures recollective memory located at the and are implicated in base of the memory disorders brain, connected to .g. thiamine e the deficiency hippocampus (Korsakoff's syndrome). Function: he basal ganglia work with the cerebral cortex T and thalamus to regulate movement and refine motor commands. hey are also implicated in forming habits and T automating routine actions. 8 Parkinson’s Disease: Diencephalon Location ey K rimary P Structure omponents C Functions ➔ A neurodegenerative disorder associated with damage to the dopamine-producing neurons in thesubstantia nigra, which Thalamus orsal D assa M elay of R connects to the basal ganglia. diencephalon intermedia, sensory thalamic nuclei and motor signals to ➔ S ymptoms include tremors, rigidity, the cortex; bradykinesia (slowness of movement), modulation and postural instability, caused by of cortical disrupted communication in the motor excitability pathways of the basal ganglia. The Forebrain: Diencephalon Hypothalamus Ventral ituitary stalk, P utonomic A diencephalon neurosecretory control, cells hormone Dicephalon Overview regulation (via the second major division of the forebrain, = pituitary gland), and located between thetelencephalonand the behavioral mesencephalon. regulation related to It surrounds thethird ventricleand contains two survival key structures: functions T halamus Hypothalamus Thalamus Greek: "inner chamber" is the dorsal part of the diencephalon, situated = near the center of the cerebral hemispheres, medial and caudal to the basal ganglia. 9 ➔ It consists of two lobes connected by a Hypothalamus bridge of gray matter called themassa intermedia. a small but critical structure located beneath the = ➔ The thalamus is the primary relay center thalamus on both sides of the ventral portion of for sensory information en route to the the third ventricle. cerebral cortex. Functions of the Thalamus P rimary Relay of Sensory Information: Almost all sensory input to the cerebral cortex is received from the thalamus. Thalamic Nuclei: The thalamus contains several nuclei, each with specific functions. Summary of Major Thalamic Nuclei and Their Functions halamic T Receives Projects Function Nucleus Input To From ateral L Eye rimary P isual V Geniculate Visual processing It regulates autonomic, endocrine, and Nucleus Cortex and relay survival-related behaviors, and connects directly to thepituitary glandthrough thepituitary stalk. edial M Inner Ear rimary P uditory A Geniculate Auditory processing Functions of the Hypothalamus Nucleus Cortex and relay 1. C ontrol of the Autonomic Nervous entrolateral Cerebellum P V rimary otor M System: Regulates involuntary bodily Nucleus Motor coordination functions like heart rate, blood pressure, Cortex and planning and digestive processes. Other Nuclei arious V idesprea W odulation of M 2. Endocrine System Regulation: Controls cortical and d cortical cortical hormone secretion via connections with subcortical areas excitability the pituitary gland. regions and 3. Behavioral Regulation: Organizes connectivity behaviors essential for species survival (e.g., feeding, mating, escape, ➔ R elay of Sensory Information: Some aggression). thalamic nuclei relay sensory information 4. Homeostatic Functions: Regulates directly to specific sensory areas in the physiological states like hunger, thirst, cortex (e.g., vision, hearing). body temperature, and sleep. ➔ Motor Function: Nuclei like the ventrolateral nucleustransmit information from the cerebellum to the motor cortex to aid in movement control. ➔ Cortical Excitability: Certain nuclei control the general excitability of the cerebral cortex through widespread projections, thus modulating alertness and attention. 10 Connection to the Pituitary Gland terminal buttons. When stimulated, these ituitary P Control Hormones Function hormones enter the bloodstream. Section Mechanism Produced/Co ➔ Examples: ntrolled ◆ Oxytocin: Influences social bonding, childbirth, lactation, and nterior A ypothalamic H onadotropic G ontrols C maternal behaviors. Pituitary -releasing hormones, other ◆ Vasopressin (Antidiuretic Gland hormones prolactin, endocrine Hormone): Regulates water somatotropic glands balance and blood pressure, and hormone plays a role in social bonding and osterior P irect neural D xytocin, O irect D parental behaviors. Pituitary connection vasopressin physiologic Gland via axons al and Key Hormones and Their Effects behavioral effects Hormone Source Target Effect Hormonal Regulation by the Hypothalamus onadotropic A G nterior onads G timulates S he hypothalamus produces hormones and T Hormones Pituitary (Ovaries/ release of sex regulates bothanteriorandposterior pituitary Testes) hormones glands. It accomplishes this via two main (e.g., methods: estrogen, testosterone) Anterior Pituitary Regulation: ➔ N eurosecretory Cells: Specialized hypothalamic neurons produce releasing Prolactin nterior A ammar M timulates S Pituitary y Glands milk hormones. production ➔ Hormonal Control Pathway: These hormones travel through a blood vessel system to the anterior pituitary, where they stimulate or inhibit the release of specific omatotropic A S nterior arious V romotes P hormones. Hormone Pituitary body growth and ➔ Examples: (Growth cells cellular ◆ Gonadotropin-Releasing Hormone) reproduction Hormone (GnRH): Stimulates release of gonadotropic hormones, affecting reproductive physiology Oxytocin osterior U P terus, timulates S and behavior. Pituitary mammar labor ◆ ProlactinandSomatotropic y glands, contractions, brain lactation, and Hormone (Growth Hormone): Act bonding directly on target tissues rather behaviors than other glands. Posterior Pituitary Regulation: asopressin V osterior K P idneys, egulates R ➔ D irect Neural Pathway: Hypothalamic (ADH) Pituitary blood water neurons extend axons directly to the vessels, retention, posterior pituitary. brain blood ➔ Hormone Release: Hormones produced pressure, and by the hypothalamus travel down axons social behaviors and are stored in the posterior pituitary's 11 Key Structures in the Tegmentum: Additional Features 1. R eticular Formation: Spans from medulla ➔ P ituitary Stalk: Connects the to midbrain, involved in sleep, arousal, hypothalamus to the pituitary gland, attention, and muscle tone. allowing for hormonal and neural 2. Periaqueductal Gray Matter: Surrounds communication. the cerebral aqueduct, involved in ➔ Optic Chiasm: Located in front of the species-typical behaviors like mating and pituitary stalk; the site where half of the aggression; modulates pain sensitivity. optic nerve fibers cross from one side of 3. Red Nucleus: Aids in motor coordination the brain to the other, integrating visual by relaying motor information from the information from both eyes. cerebral cortex and cerebellum to the spinal cord. The Midbrain: Mesencephalon 4. Substantia Nigra: Contains dopamine-producing neurons projecting to the basal ganglia; degeneration here is linked to Parkinson’s disease. The Hindbrain: Metencephalon & Myelencephalon he hindbrain is divided into two major structures: T the metencephalon (includes cerebellum and pons) and myelencephalon (includes medulla oblongata). Structure Location Function Midbrain urrounds the S Integrates sensory cerebral inputs, plays key roles aqueduct, in motor control, visual contains two and auditory reflexes, parts: tectum and processing of pain and and species-specific tegmentum behaviors. ectum T orsal part of D ousessuperior H ("roof") the colliculi(visual mesencephal reflexes, reactions to on moving stimuli) and inferior colliculi Metencephalon (auditory processing). Structure Location Function egmentum T eneath the B ontainsreticular C ("covering") tectum formation(regulates Cerebellum orsal to D Integrates visual, sleep, arousal, the pons auditory, vestibular, and attention), somatosensory inputs to periaqueductal gray coordinate movement; matter(pain damage results in jerky modulation, and exaggerated species-typical movements. behaviors),red nucleus,substantia Pons entral to V elays information from R nigra(motor control), the cerebral cortex to andventral cerebellum, cerebellum; involved in tegmental area. sleep and arousal. 12 bove a medulla C erebellum: Composed of two hemispheres and a cortex, it refines motor Component Description output to smooth and coordinate movements. It receives sensory input and Structure ube-like structure; wider at the top, T feedback about ongoing movements. narrower at the bottom; protected by ○ Damage: Leads to uncoordinated, vertebral column. exaggerated movement. Pons: Connects brain areas and includes ain M istributes motor fibers to effectors D part of the reticular formation involved in Functions (muscles and glands) and collects somatosensory information for the sleep regulation. It relays motor brain. information from the cortex to the cerebellum. Independe C apable of reflex actions independent nt Actions of the brain. Myelencephalon hite W ocated on the outside, contains L Matter myelinated axons for ascending Structure Location Function (sensory) and descending (motor) tracts. edulla M ost caudal C M ontrols vital autonomic Oblongata portion of the functions, such as ray G ocated on the inside, consists mostly L brainstem cardiovascular and Matter of cell bodies and unmyelinated respiratory regulation, and axons. muscle tone. Structure Details M edulla Oblongata: Contains part of the reticular formation; regulates essential life V ertebral Column: Composed of 24 functions (breathing, heart rate). It connects vertebrae (cervical, thoracic, lumbar) and directly to the spinal cord, marking the transition between the brain and spinal cord. fused sacral and coccygeal bones. Spinal Roots: The Spinal Cord ○ Dorsal Roots: Carry sensory information. ○ Ventral Roots: Carry motor information. Cauda Equina: Lower spinal nerves forming a bundle ("horse’s tail") due to spinal cord’s shorter length than vertebral column. 13 Structure & Function of the PNS ummary Table of Spinal Cord Components S Cranial Nerves and Functions: ➔ 1 2 pairs of cranial nerves attached to the ventral surface of the brain Component Location Function ➔ Most serve sensory and motor functions of White Matter Outer region ontains C the head and neck region ascending/de ➔ Olfactory information is received via scending olfactory bulbs myelinated ➔ The vagus nerves regulates the functions axons. of organs in the thoracic and abdominal cavities Gray Matter Inner region ontains C neuron cell O o o To Touch And Feel Very Good Vag_ _ _ AH! bodies and unmyelinated axons. auda C ower end of L undle of B Equina spinal cord spinal nerves; region site for caudal block in pelvic surgery. orsal D orsolateral D ransmit T Roots surface sensory information to the spinal cord. entral V entrolateral V ransmit T Roots surface motor commands to muscles. Spinal nerves ➔ N erves exit the vertebral column to innervate muscles and sensory receptors, with extensive branching. ➔ Afferent axons carry information toward the CNS ➔ Efferent axons send information away from the CNS. The Autonomic Nervous System A PNS branch regulating smooth muscle, = cardiac muscle, and glands. ➔ D ivided into sympathetic and parasympathetic divisions 14 Sympathetic Division ➔ A pplications:Helps to identify structural abnormalities, such as tumors, bleeding ➔ M anages arousal actions and energy (e.g., stroke), or other injuries. expenditure. ◆ E.g. CT scans of a stroke patient ➔ Coordinates the fight, flight, or freeze can reveal the extent and location mechanisms in response to stressors. of internal bleeding Parasympathetic Division ➔ P romotes storage of energy and recovery following stress. ➔ Restores bodily functions to a resting state post-arousal responses. ➔ Employs neurotransmitter acetylcholine for action. Function Sympathetic Parasympathetic Magnetic Resonance Imaging (MRI) Pupil reaction Dilates Constricts Unlike CT, MRI does not use X-rays. It uses a = strong magnetic field to align hydrogen atoms in Tear Production Ihibits Stimulates the brain, and radio waves flip these atoms to Salivatory Inhibits Stimulates measure their response, providing detailed images. Airways Constricts Stimulates ➔ U tilizes radio waves and magnetic fields Heartbeat Speeds up Slows down for internal imaging Sweating Stimualtes – ➔ P rocedure:The patient is placed in a Glucose Release Stimulates – magnetic field, and hydrogen nuclei in the body respond to radiofrequency pulses. igestive D Inhibits Stimulates The emitted energy is used to create System high-resolution brain images. lood Vessles in Constricts B _ ➔ A pplications:MRI provides detailed Skin images of the brain, distinguishing between gray matter (cell bodies) and Studying the Living Human Brain white matter (nerve fibers). It can also Noninvasive Methods reveal major fiber bundles, such as the corpus callosum. Computerized Tomography (CT) ➔ L imitations:Small fiber bundles are difficult to visualize with standard MRI. Uses X-rays to create cross-sectional images = (slices) of the brain. ➔ P rocedure:A patient’s head is placed in a doughnut-shaped ring containing an X-ray tube and detector. The X-ray beam scans the head from multiple angles, and the detector measures the radioactivity that passes through. 15 Diffusion Tensor Imaging (DTI) An advanced MRI technique that tracks the = roducing Brain Lesions Research P movement of water molecules in the brain’s white (Practices) matter. ➔ Techniques ➔ W ater molecules move randomly in all ◆ Electrical currents passed for directions unless they are within fiber lesions. bundles, where they tend to move in ◆ Excitotoxic lesion production via parallel to the direction of the fibers. excitatory amino acids. ➔ A pplications:DTI allows visualization of ◆ Sham lesions mimic procedures fiber tracts and white matter pathways in without causing damage. the brain, showing the direction and ➔ Permanent vs. Temporary Lesions orientation of axonal bundles.Modified ◆ Variability in lesions' duration and MRI technique visualizing myelinated impact on brain functioning. axon bundles using water movement. Lesion Goal Procedure Uses adiofreque R o destroy or T radiofrequency A ommonly used in C ncy Lesion inactivate a signal is applied animal studies to specific brain to the tissue, create brain region. causing it to heat lesions, allowing and destroy researchers to nearby cells. observe behavioral changes due to localized damage. xcitotoxic E To destroy n excitatory A his technique T Lesion pecific brain s amino acid (e.g., allows precise cells by kainic acid) is lesioning, Invasive Methods overstimulating injected into a especially in areas them. brain region to with complex cause selective circuits or small valuating the Behavioral Effects of Brain E neuronal target regions. Damage damage. ➔ Research Techniques hemical C emporarily T ocal anesthetics L nables reversible E ◆ Experimental Ablation Inactivation inactivate a specific brain or drugs are infused into the manipulation of brain function, Inactivation of brain region to region of interest often used in portions to observe observe its to inhibit neural animal research. effects on activity without behavioral consequences. behavior. permanent ◆ Lesion Studies damage. Brain damage with observational tracking of tereotaxic S o place T stereotaxic A sed in U subsequent behaviors. Surgery electrodes or atlas is used to conjunction with cannulas in guide the various lesion ➔ Purpose precise locations surgeon’s methods to study ◆ Identify specific functions of distinct within the brain. placement of the effects of brain instruments in damage in brain areas and analyze collective the brain. This animals. functional behavior. technique is critical for targeting specific brain regions for lesions or other interventions. 16 Title Subtitle Subsubtitle 17
