Neurobiology of Hunger and Emotion

The idea that the brain constantly monitors the amount of body fat and uses this information to regulate appetite and energy expenditure.

A hormone produced by fat cells that signals to the brain about the body's energy stores, promoting feelings of fullness (satiety) and reducing appetite.

Signals that make us feel full, inhibiting further eating.

A condition characterized by a loss of appetite and significant weight loss, often caused by damage to the lateral hypothalamus (LH).

An eating disorder characterized by recurrent episodes of binge eating followed by purging behaviors (e.g., vomiting, laxative abuse) to prevent weight gain.

Hormonal responses initiated by the pituitary gland, affecting other glands and regulating various bodily functions. Examples include TSH (thyroid stimulating hormone) and ACTH (adrenocorticotropic hormone).

A state of mechanical stretching of the stomach wall, often triggered by eating. It's a key signal for satiety.

The stage of eating where absorbed nutrients from the intestines enter the bloodstream. Insulin levels peak during this phase.

Hypovolemia refers to a decrease in the volume of blood circulating in the body.

Vasopressin, also known as antidiuretic hormone (ADH), plays a crucial role in regulating water balance. When blood volume decreases, vasopressin acts on the kidneys to increase water reabsorption, helping to restore blood volume.

Diabetes insipidus is characterized by excessive thirst (polydipsia) and the production of large volumes of dilute urine (polyuria). This condition arises due to a deficiency in vasopressin, the hormone responsible for regulating water reabsorption in the kidneys.

The OVLT (Organum Vasculosum of the Lamina Terminalis) is a brain region that detects changes in blood osmolarity. When blood becomes hypotonic (increased salt concentration), the neurons in the OVLT become excited, leading to the release of vasopressin by magnocellular neurosecretory cells.

Genetic sex is determined at the moment of conception, when the sperm fertilizes the egg.

Humans have 46 chromosomes, arranged in 23 pairs.

X-linked disorders arise from a defective gene located on the X chromosome. Males are more susceptible to these disorders because they only have one X chromosome, while females have two X chromosomes, and one can compensate for a defect on the other.

The SRY gene on the Y chromosome encodes a protein called testis-determining factor (TDF). This protein plays a crucial role in male sex development.

The preoptic area of the anterior hypothalamus is a region of the brain where the most distinct sexual dimorphisms in mammals are clustered, particularly in the third ventricle.

Oxytocin and vasopressin play a significant role in influencing pair bonding and parenting behaviors in mammals.

In male prairie voles, an increase in vasopressin levels is observed, while the specific hormonal changes in females are not explicitly mentioned in the excerpt.

Sexual dimorphism refers to the biological differences between males and females of a species. An example is the presence of larger bulbocavernosus muscles in males than females.

The vocal control region is a specific brain area responsible for song production in zebra finches.

Sex hormones can have activating effects on the brain. For example, during lactation in rats, the sensory maps of the skin, specifically the area around the nipples, expand.

Experimentally administering estrogen to newborn mice led to an increase in neurite outgrowth in the hypothalamus, suggesting a role of estrogen in brain development.

A gynandromorph is an organism that possesses both male and female tissues, often resulting from genetic abnormalities.

A pathway in the spinal cord responsible for controlling posture and locomotion, involving the tectospinal, vestibulospinal, pontine, and medullary reticulospinal tracts.

A tract within the ventromedial pathway that controls head orientation in response to stimuli.

Tracts that work together to balance the body when the head turns. They are a part of the ventromedial pathway.

A tract within the ventromedial pathway that helps resist gravity and maintain posture.

A pathway in the spinal cord responsible for voluntary movement, involving the rubrospinal tract in some primates.

A cortical area responsible for primary motor control, known as M1.

Higher motor areas involved in motor planning and strategy, located in the frontal lobe and responsible for 'getting ready' for movement.

A structure in the forebrain that plays a crucial role in selecting and initiating movement.

The part of the basal ganglia that receives input from the cortex.

A symptom of both Parkinson's and Huntington's diseases, characterized by cognitive decline.

The hypothalamus controls the release of many hormones and is therefore considered the "master gland" of the endocrine system. It plays a vital role in regulating various bodily functions, including stress response, appetite, and energy expenditure.

Cortisol is a steroid hormone produced by the adrenal glands during stressful situations. It mobilizes energy reserves by breaking down stored carbohydrates and suppresses the immune system to prioritize energy allocation towards fighting the stressor.

The adrenal medulla, part of the adrenal gland, releases adrenaline (epinephrine) into the bloodstream. This hormone is crucial for the "fight or flight" response, triggering rapid physiological changes like increased heart rate, blood pressure, and alertness.

The autonomic nervous system (ANS) is responsible for regulating involuntary bodily functions. It has two branches: sympathetic and parasympathetic.

Lower motor neurons, essential for muscle contraction, are located in autonomic ganglia, which are nerve clusters outside the CNS.

The enteric nervous system (ENS) is a complex network of neurons located in the lining of the digestive tract. Known as the "little brain," it can operate independently and controls important digestive processes.

The locus coeruleus (LC) is a region in the brain stem that releases the neurotransmitter norepinephrine. It plays a crucial role in attention, arousal, and responding to salient stimuli.

The raphe nuclei are a group of neurons in the brainstem that synthesize and release serotonin. They are involved in regulating mood, sleep, and wakefulness.

A type of memory that is responsible for learning and remembering motor skills and procedures, like riding a bike or playing the piano. It is not dependent on conscious awareness and is often acquired through practice and repetition.

A type of neuron located in the hippocampus that fires when an animal is in a specific location in its environment. They act as a kind of spatial map, helping animals navigate and remember locations.

A condition characterized by a gradual loss of neurons in the brain, leading to a decline in cognitive abilities, including memory. It is often associated with damage to the hippocampus and other brain structures involved in memory formation.

A type of memory that is responsible for remembering personal experiences and events that happened in a specific time and place. It is often called autobiographical memory and is highly dependent on the hippocampus.

The gradual decline in the strength of a memory over time. This is a natural process that affects all types of memories, but it can be slowed down by repeated retrieval and rehearsal.

A form of synaptic plasticity that involves a long-lasting strengthening of the connection between two neurons, typically as a result of repeated stimulation. This process is thought to underlie learning and memory.

A form of synaptic plasticity that involves a long-lasting weakening of the connection between two neurons, typically as a result of infrequent or weak stimulation. This process is thought to contribute to forgetting and the ability to filter out irrelevant information.

The preoptic area of the anterior hypothalamus is a region in the brain where the most distinct sexual dimorphisms in mammals are clustered, particularly in the 3rd ventricle.

Oxytocin and vasopressin are hormones that play a significant role in influencing pair bonding and parenting behaviors in mammals.

The bulbocavernosus muscles are larger in males than females, demonstrating a clear (anatomical) sexual dimorphism related to reproductive function.

The vocal control region is a specific brain area responsible for song production in zebra finches.

Sex hormones, like estrogen, can influence brain development, particularly in the hypothalamus. For example, administering estrogen to newborn mice leads to increased neurite outgrowth in the hypothalamus.

The Papez circuit is a network of brain structures involved in emotional processing. It includes the neocortex, fornix, hippocampus, hypothalamus, anterior nuclei of the thalamus, and cingulate cortex.

The amygdala, located in the temporal lobe, is a brain region involved in processing fear and aggression. Lesions to the amygdala can lead to reduced fear responses and decreased aggression.

The ability to focus on one aspect of sensory input, ignoring distractions.

A type of attention that is goal-directed and driven by internal factors, such as our intentions and expectations.

A region in the thalamus involved in attention that helps shift attention to specific locations in the visual field.

A state of increased brain activity observed in the Default Mode Network (DMN) during periods of rest, daydreaming, and internal mentation.

A hypothesis suggesting that the Default Mode Network (DMN) is primarily active when we engage in internal mentation, such as daydreaming, thinking, and retrieving autobiographical memories.

A region of the brain that plays a crucial role in selecting and initiating movement.

A type of aphasia characterized by difficulty with speech production, often resulting in slow, labored speech and grammatical errors.

A type of aphasia characterized by difficulty with speech comprehension, often resulting in fluent, but nonsensical speech.

A condition where an animal displays aggression but does not actually act upon it, often seen after removal of the cerebral hemispheres (telencephalon).

The lateral region of the hypothalamus, responsible for triggering predatory aggression, often observed when stimulated experimentally.

Characterized by high levels of sympathetic nervous system activity, vocalizations, and threatening or defensive postures. Often associated with emotional aggression.

The stimulation of the medial region of the hypothalamus triggers aggressive behavior.

A measurement technique that provides insights into the electrical activity of the cerebral cortex, particularly the dendrites of pyramidal neurons.

The brain activity during sleep, characterized by synchronized rhythms, suggesting a disconnection of the cortex from sensory input.

The most extreme form of synchronized electrical activity in the brain, often associated with seizures.

The temporal lobes of the cortex are often implicated in partial seizures, which can potentially lead to experiences like déjà vu or hallucinations.

The hypothalamus controls the release of various hormones and is considered the 'master gland' of the endocrine system, regulating crucial bodily functions like stress response, appetite, and energy expenditure.

Cortisol, a steroid hormone, is released during stressful situations. It mobilizes energy reserves by breaking down stored carbohydrates and suppresses the immune system to prioritize energy allocation towards dealing with the stressor.

The adrenal medulla, part of the adrenal gland, releases adrenaline (epinephrine) into the bloodstream. This hormone is crucial for the 'fight or flight' response, triggering rapid physiological changes like increased heart rate, blood pressure, and alertness.

The autonomic nervous system (ANS) controls involuntary bodily functions. It has two branches: sympathetic and parasympathetic.

The lower motor neurons involved in muscle contraction reside in autonomic ganglia, which are nerve clusters outside the CNS.

The enteric nervous system (ENS), known as the 'little brain', is a complex network of neurons located in the lining of the digestive tract. It can operate independently and controls important digestive processes.

The locus coeruleus (LC) in the brainstem releases norepinephrine, a neurotransmitter crucial for attention, arousal, and responding to significant stimuli.

The raphe nuclei in the brainstem synthesize and release serotonin, a neurotransmitter involved in regulating mood, sleep, and wakefulness.

A type of memory that is responsible for learning and remembering motor skills and procedures, such as riding a bike or playing the piano. It is not dependent on conscious awareness and is often acquired through practice and repetition.

A type of neuron located in the hippocampus that fires when an animal is in a specific location in its environment. They act as a kind of spatial map, helping animals navigate and remember locations.

A gradual loss of neurons in the brain, leading to a decline in cognitive abilities, including memory. This can often be linked to damage to the hippocampus and other brain structures critical for memory formation.

A form of synaptic plasticity that involves a long-lasting strengthening of the connection between two neurons, typically as a result of repeated stimulation. This process is thought to underlie learning and memory.

A form of synaptic plasticity that involves a long-lasting weakening of the connection between two neurons, typically as a result of infrequent or weak stimulation. This process is thought to contribute to forgetting and the ability to filter out irrelevant information.

The value of NMDA receptor activation, between that required for LTD and LTP, at which there is no net change. This means that the synapse is neither strengthened nor weakened.

The concept that the rules of synaptic plasticity change depending on the history of synaptic or cellular activity. This means that past experiences can influence how synapses are modified in the future.

Graceful degradation refers to what happens to a memory if some neurons in that neuronal network storing information start dying? It means that representations blend together and memories can become confused with each other, but don't disappear entirely.

A cortical area in the brain responsible for initiating voluntary movement. Known as M1.

A tiny area in the brain that plays a crucial role in regulating many vital functions: body temperature, blood pressure, hunger, thirst, among others. Think of it as the 'master control' for the body's internal environment.

The preoptic area, located in the anterior hypothalamus, is where the most distinct differences in brain structure between males and females are found, particularly in the third ventricle.

The bulbocavernosus muscles, which are larger in males than females, are a clear example of sexual dimorphism related to reproductive functions.

The inability to produce the movements needed for speech, even though the person understands language.

A gene that plays a critical role in human language development. Mutations in this gene can lead to language impairments.

The partial or complete loss of language abilities as a result of damage to the brain, typically due to stroke or injury.

A region in the left frontal lobe of the brain that is crucial for speech production.

A region in the left temporal lobe of the brain that is essential for understanding language.

A type of aphasia that results from damage to the connection between Broca's area and Wernicke's area. It's characterized by difficulty repeating words and phrases.

The amygdala, located in the temporal lobe, is crucial for processing fear and aggression. Damage to the amygdala can lead to reduced fear responses and decreased aggression.

The ability to focus on specific sensory information, ignoring distractions.

A type of attention driven by internal goals, like your intentions and expectations.

A region in the thalamus that helps shift attention to specific locations in the visual field.

Increased brain activity in the Default Mode Network (DMN) during periods of rest, daydreaming, and internal thought.

The hypothesis suggests that the Default Mode Network (DMN) is primarily active during internal mental processes, like daydreaming, thinking, and recalling personal memories.

A region of the brain that plays a critical role in selecting and initiating movement.

Characterized by difficulty with speech production, leading to slow, labored speech and grammatical errors.

The collection of alpha motor neurons that innervate a single muscle.

One alpha motor neuron and all the muscle fibers that it innervates.

Contraction of one set of muscles accompanied by relaxation of the antagonist muscles.

The reflex that prevents you from falling when you suddenly lift one foot off the ground in response to pain.

A group of neurons in the spinal cord that produces rhythmic patterns of motor activity without input from the brain.

A network of brain regions involved in focusing attention, including the prefrontal cortex, FEF, and lateral intraparietal cortex (LIP).

The lateral intraparietal cortex (LIP) plays a crucial role in attention by constructing a priority map that highlights the most salient stimuli, helping us direct our focus to the most important things.

Stimulating neurons in the FEF (frontal eye field) can improve our ability to detect stimuli by lowering the threshold for detection.

The minimal neural event required for the subjective experience of consciousness. It's about understanding the link between brain activity and our conscious awareness.

Anxiety disorders are the most common psychiatric disorder affecting a large portion of the population.

CRH (corticotropin-releasing hormone) neurons in the parvocellular region of the PVN (paraventricular nucleus) in the hypothalamus are activated during the humoral stress response.

Injecting CRH into animals causes anxiety-related behavior, likely mimicking the 'fight or flight' response.

The bed nucleus of the stria terminalis plays a crucial role in anxiety disorders by activating the HPA axis and contributing to the stress response.

The OVLT (Organum Vasculosum of the Lamina Terminalis) is a brain region that detects changes in blood osmolarity. When blood becomes hypotonic (increased salt concentration), the neurons in the OVLT become excited, leading to the release of vasopressin by magnocellular neurosecretory cells.

Benzodiazepines (benzos) and barbiturates are medications often prescribed for epilepsy and seizures. Their primary mechanism of action is to enhance the inhibitory effects of GABA, a neurotransmitter that reduces neuronal activity.

Non-REM sleep is characterized by a lack of rapid eye movements, reduced brain activity, and a general absence of dreaming. It is further divided into stages 1 to 4.

Ultradian rhythms refer to the cyclical pattern of alternating sleep stages during the night, predominantly between slow-wave sleep (around 75%) and REM sleep (around 25%).

During REM sleep, the muscles controlling eye movements show heightened activity leading to rapid eye movements. However, the rest of the body becomes paralyzed.

REM sleep is called paradoxical sleep because the brain activity resembles that of wakefulness, but the body remains physically inactive. You can't act on your dreams during REM.

The Activation-Synthesis Hypothesis proposes that dreams are a result of the brain attempting to make sense of random neural activity occurring in the pons during REM sleep. These random signals are then associated with memories and thoughts in the cortex.

The sleep and wake neurons are part of the diffuse modulatory neurotransmitter system, which is responsible for regulating arousal and other brain functions.

The brain regions and associated neurotransmitters that are associated with changes in awakening and arousal states include the raphe nuclei (serotonin), the locus coeruleus (norepinephrine), and areas within the brainstem and forebrain (acetylcholine).

A neurological procedure where one hemisphere of the brain is temporarily anesthetized to determine which hemisphere controls speech.

The inability to produce the movements needed for speech, even though the person understands language.

A gene that plays a critical role in human language development. Mutations in this gene can lead to language impairments.

A type of attention that is goal-directed and driven by internal factors, such as our intentions and expectations.

A state of increased brain activity observed in the Default Mode Network (DMN) during periods of rest, daydreaming, and internal mentation.

The inability to form new memories after a brain injury or trauma.

The inability to recall events that occurred before a brain injury or trauma.

A type of memory that allows us to consciously recall facts, events, and personal experiences.

The process of transferring information from short-term memory to long-term memory.

A type of memory involved in holding information temporarily, such as remembering a phone number while dialing it.

A memory test that assesses an individual's ability to recognize a previously encountered item. Often used to study recognition memory.

A test that evaluates working memory in humans. It involves sorting cards based on changing rules, requiring flexibility in thinking and problem-solving.