Neuroscience and Clinical Psychology Lecture Notes PDF

Neuroscience and Clinical Psychology The five major divisions of the brain Major structures of the brain  Learning outcomes You will be familiar with the 5 major subdivisions of the brain You will be familiar with the function of some nuclei within those divisions...

Neuroscience and Clinical Psychology The five major divisions of the brain Major structures of the brain  Learning outcomes You will be familiar with the 5 major subdivisions of the brain You will be familiar with the function of some nuclei within those divisions You will be familiar with the collective function of brain ‘systems’ You will gain insight into some approaches by which scientists study brain function Title  Terminology 1. Anatomical ‘directions’ Dorsal/ventral (towards the back/belly) Anterior/posterior (towards the front/back) Rostral/caudal (towards the beak/tail) Medial/lateral (towards the middle/side) Title  Terminology 2. Planes of section Title  Terminology Basic subdivisions: Spinal cord, then…. Hindbrain Midbrain Forebrain ‘Encephalon’ = [Gk] within the head Brain stem = hindbrain + midbrain Title  Hindbrain A. Hindbrain [myelencephalon + metencephalon] Myelencephalon [Gk ‘marrow’] = medulla oblongata Title  Hindbrain Contains nuclei which (amongst other things) control: Respriation [respiratory groups; respiratory rhythm] Tongue musculature [hypoglossal nucleus] Blood pressure and heart rate [nucleus ambiguus] Nucleus ambiguus gives rise to part of the vagus nerve Vagus = part of autonomic nervous system (ANS) ANS controls: Heart muscle Smooth muscle [e.g. blood vessels] Glands [e.g. adrenal gland – adrenaline] Title  Hindbrain Metencephalon [Gk ‘after’] = pons and cerebellum Title  Hindbrain Pons [L ‘bridge’] contains nuclei which (amongst other things) are involved in sleep and arousal E.g. locus coeruleus [noradrenaline] Cell activity closely related to level of arousal Mean firing rate (Hz x 10) Title  Hindbrain Cerebellum [L ‘little brain’] Integrates sensory [visual, auditory, vestibular and somatosensory] infor- mation; uses this to modify motor output Coordinates and smoothes movements Damage – movements = jerky, poorly coordinated + exaggerated [impairs standing and walking] Title  Midbrain Mesencephalon [Gk ‘middle] = tectum and tegmentum Tectum [L ‘roof’] Consists of inferior and superior colliculi [L ‘little hills’] Inferior colliculi – part of auditory system Superior colliculi – part of the visual system; in primates, involved in production of saccades [rapid eye movements] Title  Midbrain Tegmentum [L ‘covering’]: Contains 3 major structures: Periaqueductal grey – involved in species-typical behaviours E.g. during mating…. Female rat assumes a posture prior to mating - lordosis (reflex) - arching of back and elevation of hindquarters Title  Midbrain Stimulation (electrical) of periaqueductal grey: effect on lordosis Lordosis elicited by ‘manual cutaneous stimulation’ of hindquarters [each data point], in absence and presence of PAG stimulation; scored from 0 (absent) to 3 (strong) Cutaneous stimulation + PAG stimulation higher score Other components of tegmentum: Red nucleus - part of motor system [muscles of shoulder an upper arm] Substantia nigra - part of motor system Title  Half time quiz What disorder is associated with the death of neurons in the substantia nigra? A.Parkinson’s disease B.Huntington’s disease C.Alzheimer’s disease D.Motor neuron disease Intermission  Half time quiz What disorder is associated with the death of neurons in the substantia nigra? A.Parkinson’s disease B.Huntington’s disease C.Alzheimer’s disease D.Motor neuron disease  Forebrain Diencephalon [Gk ‘between’] 2 most important structures: Thalamus Hypothalamus Thalamus [Gk ‘inner chamber’] Divided into nuclei (neurons of similar size + shape) Some = sensory relay nuclei; transmit information from receptors to cortex [E.g. dorsal lateral geniculate (‘knee’) nucleus; receives from retina; projects to V1] Other [non-sensory] nuclei – function unknown; project [mainly] to cortex  Forebrain Hypothalamus [Gk ‘below’ thalamus] Organises autonomic and glandular aspects of responses related to survival [the 4 ‘Fs’]: Fighting, feeding, fleeing….. and mating - also homeostasis [e.g. temperature; blood glucose] Contains many nuclei…. …. with distinct functions (e.g.):  Forebrain Suprachiasmatic nucleus – circadian rhythms Rhythms with a period of about 24 hrs [L. circa = about; dies = day] Top: unoperated control Bottom: SCN lesion [bilat] A = activity; D = drinking Recorded over 5 days; SCN lesion no entrainment  Forebrain Telencephalon [Gk ‘end’]; most of the 2 cerebral hemispheres [connected by corpus callosum] Mediates the most complex functions Consists [mainly] of: Limbic system Basal ganglia Cerebral cortex Cerebral cortex; four lobes: Frontal Temporal [L ‘temple’] Parietal [L ‘wall’] Occipital [L ‘ob’= in back of; ‘caput’ = head]  Forebrain Some areas receive sensory information (e.g.): Primary visual cortex - occipital lobe Primary auditory cortex - temporal lobe Primary somatosensory cortex - parietal lobe Movement: primary motor cortex [frontal lobe] Stimulation – muscular movement M1 = somatotopic [Organised according to a map of the body]  Forebrain Primary sensory and motor areas send information to adjacent regions – association cortex Accomplishes what is done between sensation and action: E.g…. Perceiving, learning/remembering, planning Damage to V1 – blindness Damage to visual association cortex – more complex deficits Damage to human visual association cortex can cause visual agnosia [‘failure to know’] E.g. associative visual agnosia Can ‘perceive’ objects [copy them], but can’t say what they are, or what they’re for  Forebrain Area rostral to motor association cortex = prefrontal cortex Involved in planning and emotional behaviour E.g. Phineas Gage, first reported by Harlow (1868) A dynamite worker; explosion that blasted an iron tamping bar (~1.0 m x 3 cm) through the front of his head Damaged his left frontal lobe:  Forebrain His behaviour changed completely after accident; after accident: ‘He is fitful, irreverent, indulging at times in the grossest profanity, manifesting but little deference to his fellows, impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating’  Forebrain 90% = neocortex; what about the rest? Hippocampus [‘sea horse’; 3 layers (archicortex)]; part of the…. Limbic system – term coined by MacLean (1949) [physiologist] Collection of structures involved in emotion and memory; consists of: Hippocampus Amygdala [Gk ‘almond’] Cingulate cortex [L ‘girdle] - medial Septum [L ‘enclosing’] Plus…. Mammillary bodies [L ‘Breast’] - part of dien’lon  Forebrain Finally, basal ganglia – consists of: Caudate nucleus, Putamen, Globus pallidus Plus…. Substantia nigra [part of mesencephalon] Subthalamic nucleus [part of diencephalon] Important group of nuclei concerned with movement  Summary The brain consists of 5 basic subdivisions: Mylencephalon Metencephalon Mesencephalon Diencephalon Telencephalon Each has its own set of functions, from vegetative to more complex as you travel forward Nuclei are sometimes organised into systems which cross the boundaries between subdivisions  Summary Pinel – Chapter 3 (“Anatomy of the nervous system”)