Physiological Psychology: Neuroanatomy, Memory Disorders, and Neurodegenerative Diseases

Comprehensive vocabulary flashcards covering neuroanatomy, cortical mapping, ventricles, neurotransmitter pathways, Korsakoff syndrome, Alzheimer's disease, Parkinson's disease, and Huntington's disease.

Korsakoff Syndrome

A condition characterized by severe anterograde amnesia, retrograde amnesia of $3\text{--}30$ years, and confabulation, caused by brain damage resulting from thiamine (vitamin B1) deficiency, often seen in severely alcoholic individuals due to poor diets.

Confabulation

The act of inventing a story to explain one's present situation, commonly observed as a symptom in patients with Korsakoff syndrome and diencephalic damage.

Jimmy, the Lost Mariner

A Korsakoff syndrome case study of a $49$-year-old man who experienced severe retrograde amnesia and believed he was still $19$ years old.

Anatomy of Memory Pathway

The circuit linking memory structures: hippocampus $\rightarrow$ (fornix) $\rightarrow$ mammillary bodies $\rightarrow$ (mammillothalamic tract) $\rightarrow$ anterior thalamus.

Hippocampal vs. Diencephalic Damage

While both types of damage cause severe anterograde amnesia, diencephalon damage (specifically to mammillary bodies and thalamus) selectively leads to confabulation and greater retrograde amnesia.

Neurofibrillary Tangles

Microscopic histological abnormalities inside the cytoplasm of neurons consisting of abnormal neurofilaments (structural fibers that provide cell shape), characteristic of Alzheimer's disease.

Senile Plaques

Microscopic abnormalities that build up around degenerating axons and dendrites, centered around an accumulation of Amyloid protein.

Familial Alzheimer's Disease (FAD)

A subset of Alzheimer's disease ($20\text{--}40\%$ of cases) inherited clearly as an autosomal dominant trait, typically characterized by early onset in an individual's $40$s.

Basal Forebrain Cholinergic System

A region anterior and lateral to the hypothalamus surrounding the anterior commissure containing two key cholinergic nuclei—the septum (projecting via fornix to the hippocampus) and the nucleus basalis of Meynert (projecting to all cortex and hippocampus)—which undergo selective cell loss in Alzheimer's disease.

Scopolamine

A cholinergic antagonist selective for the muscarinic subtype of acetylcholine (ACh) receptors that induces transitory anterograde amnesia in animals and humans.

Amyloid Precursor Protein (APP) Gene

A gene isolated on chromosome $21$ whose defective forms or overexpression (as seen in Trisomy $21$ / Down's syndrome individuals who reach their $30$s) contribute to Alzheimer's disease neuropathology.

Physostigmine

An acetylcholinesterase (AChE) inhibitor used experimentally to increase acetylcholine levels in Alzheimer's patients, limited by a short half-life and adverse side effects.

Arecoline

An acetylcholine muscarinic receptor agonist that has produced modest but clear positive effects in Alzheimer's treatment, though limited by short half-life and side effects.

Cerebral Cortex

The outer covering ('bark') of the brain, approximately $1.5\,\text{mm}$ thick and constituting $80\%$ of the brain, responsible for awareness and intelligence.

Longitudinal Fissure

A deep cortical groove that separates the left cerebral hemisphere from the right cerebral hemisphere.

Transverse Fissure

A prominent fissure that separates the cerebellum from the cerebrum.

Calcarine Sulcus

The sulcus located in the occipital lobe surrounded by tissue responsible for the primary sense of vision.

Transverse Gyri of Heschl

Cortical gyri situated in the temporal lobe responsible for audition (hearing).

Uncus

A structure in the temporal lobe that processes olfactory (smell) sensations.

Broca's Area

A region in the frontal lobe responsible for language production, consisting of the pars orbitalis, pars opercularis, and pars triangularis.

Wernicke's Area

An area located in the parietal/temporal region responsible for language comprehension.

Wilder Penfield

A neurosurgeon who systematically mapped the precentral and postcentral gyri (the sensory-motor strip) via electrical stimulation, demonstrating contralateral and topographical representation.

Cortical Homunculus

A distorted 'map-like' topographical representation of the human body laid out along the primary motor cortex and primary somatosensory cortex.

Projection Map

A map showing inputs and outputs of cortical areas, divided into primary (direct sensory input/motor output), secondary (indirect sensory input adjacent to primary), and tertiary (everything else) zones.

Cytoarchitectonic Map

A cortical map based on the detailed characterization of cellular structures and laminar organization across the cortex's $6$ layers.

Pyramidal Cells

The primary output neurons of the cerebral cortex, with the largest found in layer $5$ projecting to the basal ganglia and spinal cord, and layer $6$ projecting to the thalamus.

Stellate Cells

Interneurons that make local connections within cortical columns; present across all cortical layers and densely concentrated in layer $4$ receiving afferent input.

Corpus Callosum

The largest white matter tract and commissure in the brain connecting the cerebral hemispheres, featuring a prominent anterior bend called the genu.

Anterior Commissure

A commissural tract that connects the two temporal lobes at a specific point.

Diencephalon

The 'tween brain' division containing the thalamus (processes all sensory information except olfactory), the hypothalamus (pleasure center, homeostatic drives), and the subthalamus (contains glutamate).

Superior and Inferior Colliculi

Midbrain (mesencephalon) structures where the superior colliculus receives visual sensory information and the inferior colliculus receives auditory sensory information.

Medulla Oblongata

A hindbrain (rhombencephalon) structure controlling involuntary vital reflexes, including breathing, sneezing, blinking, and digestion.

Reticular Formation

A brainstem structure that regulates arousal and sleep-wake patterns.

Cerebrospinal Fluid (CSF)

Fluid produced within the ventricles that cushions the brain from mechanical shock, provides buoyancy, and acts as a reservoir of hormones and nutrients.

Septum Pellucidum

A thin membrane that separates the two lateral ventricles.

Amygdala

A limbic system structure that controls anger and defensiveness and activates defensive postures.

Raphe Nuclei

Serotonergic nuclei consisting of rostral raphe nuclei (producing serotonin utilized throughout the brain) and caudal raphe nuclei (producing serotonin utilized in the cerebellum and spinal cord).

Hallmark Motor Symptoms of Parkinson's Disease

A clinical tetrad comprising resting tremors, rigidity, bradykinesia (slow movement), and akinesia (poverty of movement).

Tyrosine Hydroxylase

The enzyme that catalyzes the first synthetic conversion in the dopaminergic pathway, converting tyrosine into L-DOPA.

D2 Autoreceptor

A presynaptic dopaminergic receptor that mediates negative feedback by detecting released dopamine and inhibiting further synthesis and release.

Carbidopa

A peripheral amino acid decarboxylase (AAD) inhibitor co-administered with L-DOPA to prevent peripheral conversion to dopamine, allowing more L-DOPA to cross the blood-brain barrier.

Bromocriptine

A direct $D_2$ dopamine receptor agonist used to treat Parkinson's disease, effective but associated with side effects such as low blood pressure, depression, and low sex drive.

Huntington's Disease

An autosomal dominant neurodegenerative disorder linked to chromosome $4$ that leads to progressive choreiform motor disturbances, psychological changes, and death within $15\text{--}20$ years.

CAG Trinucleotide Repeats

Unstable repeating trinucleotide sequences on the short arm of chromosome $4$; individuals require $23$ or more repeats to manifest Huntington's disease, with over $64$ repeats causing the juvenile form.

Nancy Wexler

A researcher who mapped Huntington's disease by studying over $11{,}000$ descendants of Maria Concepcion near Lake Maracaibo, Venezuela, tracing the condition to an English sailor progenitor from the late $1600$s.

Huntington's Underlying Biological Mechanism

The selective degeneration of striatal neurons leading to an absence of GABAergic inhibitory transmission to the globus pallidus and substantia nigra, disinhibiting the motor thalamus and motor cortex.