Biological Bases of Behavior Cheat Sheet (DRAFT) by FernandaJess

Receives and processes sensory inform­ation, initiates responses, stores memories, and generates thoughts

The largest part of the brain, made up of the cerebral cortex and other struct­ures. The cerebrum is divided into two hemisp­heres.

Connects the cerebrum and cerebellum to the spinal cord. The brainstem controls uncons­cious processes like sleep.

Forebrain

Processes sensory inform­ation, helps with reasoning and proble­m-s­olving, and regulate autonomic, endocrine, and motor functions

Hindbrain

Helps regulate automatic functions, relay sensory inform­ation, and maintain balance and equili­brium

(Primitive brain), regulates emotions (basic survival instin­cts), influences memori­es/­lea­rning, and motivation (basic drives).

Stores memories, consol­idation of conscious memories, stores new inform­ation and events as lasting memories

Maintains the body's homeos­tasis, (regulates temper­ature, hunger, thirst, sleep-wake cycle). Produces hormones that stimulate or inhibit the release of hormones from the pituitary gland.

Motor learning, executive functions and coordi­nation of movement, posture, inhibitory (allows us to be still)

Involved in regulating emotions, processing pain, and regulating autonomic motor function.

Controls the body's circadian rhythms

Involved in many high-level functions, such as reasoning, emotion, thought, memory, language and consci­ous­ness.

Primary sensory areas that process somato­sensory inform­ation, sensations of touch, pain, heat, and propri­oce­ption.

Visual percep­tion, visual interp­ret­ation, and reading

language, speech, and cognitive tasks. Includes broca's area

Integr­ation center for all sensory inform­ation and executive functions (decision making, planning, working memory, person­ality expres­sion, social behavior, speech and language). Person­ality center

Directing attention, visual & spatial skills

Verbal memory and language compre­hen­sion. Includes wernicke’s area.

Language compre­hension = receives auditory signals from the ear and processes them to understand the meaning of spoken words

Somatic Nervous System:

Sends and receives sensory messages that control voluntary motor movement of the skeletal muscles

Primary Function:

Maintain homeos­tasis (e.g., digestion, heart rate, & breathing)

Dominates during rest state, directs mainte­nance activities (e.g., rest and rumina­tion)

A major nerve in the parasy­mpa­thetic nervous system that helps regulate heart rate, digestion, and emotional responses.

Delirium

Parkin­son's Disease

Pseudo­dem­entia

Most often arises in people with AUD

Caused by thiamine deficiency (vitamin B1)

Risk:

If left untreated, WE can lead to Korsakoff syndrome (KS)

The disorder is associated with patients fabric­ating stories in the setting of clear consci­ous­ness. Confab­ula­tions can be sponta­neous or provoked

Symptoms:

Memory distur­bances in which there are signif­icant deficits in antero­grade and retrograde memory

Features:

Movement disorder with tremors, rigidity, bradyk­inesia, shuffling gait, and neurop­syc­hiatric symptoms (e.g., depres­sion, neuroc­ogn­itive disorder).

Treatment & Psycho­pha­rma­cology

Carbidopa -

Reduces Levodopa side effects (e.g., nausea, hypote­nsion) and enhances its effect­ive­ness.

Enzyme Inhibitors -

MAO-B and COMT inhibitors slow dopamine breakdown.

Antich­oli­nergics -

Reduce tremors and muscle rigidity

Defini­tion:

The most common major neuroc­ogn­itive disorder (NCD), accounting for up to 80% of cases.

Neurop­ath­ology:

Acetyl­choline deficiency, affecting learning and memory; Amyloid plaques & neurof­ibr­illary tangles; Damage to the hippoc­ampus and amygdala

Symptoms

Disori­ent­ation, confusion, impaired judgment, behavioral changes, motor and gait issues

Alzhei­mer's disease:

The most common type, charac­terized by the accumu­lation of amyloid plaques and tau tangles in the brain

Lewy body dementia:

Charac­terized by the presence of abnormal protein deposits called Lewy bodies in the brain.

Mixed dementia:

A combin­ation of two or more types of dementia

Cognitive impairment in older adults due to depression, mimicking a neuroc­ogn­itive disorder (NCD).

Patients often deny memory issues

Patients acknow­ledge memory loss

REM sleep decreases with age:

Newborns: 50%; 5-year­-olds: 20–25%; Older adults: 18%

Originates in the:

also the reservoir of our over-l­earned motor patterns, like riding a bike, automatic daily habits, backing out of the driveway, etc.

Hypoki­netic

Slow or reduced movements (e.g., parkin­son's disease, dementia with lewy bodies)

Cause:

Genetic disorder causing degene­ration of basal ganglia neurons

Onset:

Typically 40–50 years; often passed down before symptoms appear

Cause:

Damage to the Substantia Nigra, caudate nucleus, and putamen, dopami­ne-rich brain areas essential for movement and mood regulation

Possible Cause:

Bacterial infections (e.g., from foodborne pathogens) may travel via the Vagus nerve, leading to inflam­mation and degene­ration

Treatment

may aid movement and mood regulation

Brain Area:

basal ganglia, frontal lobes and cortex

Impaired coordi­nation, balance, and speech

Inability to perform skilled movements or gestures (e.g., difficulty winking)

Impaired speech or language compre­hension

Damage to Wernicke’s area (left temporal lobe); speech is not understood

Damage to neural pathways connecting these areas, affecting verbal repetition

Common Cause:

Likely damage to the hippoc­ampus, thalamus, or other memory retrieval areas

Common Cause:

Brain damage from strokes, injuries, dementia, or neurol­ogical disorders

Difficulty recogn­izing faces

Direct blow to the head, often blood vessels are torn so blood flow is blocked, tissue dies

Aftere­ffects of Head Trauma:

Can cause memory impair­ments (post-­tra­umatic amnesia, persistent memory deficits), executive functi­oning distur­bances, and person­ality changes

Aftere­ffects of Concus­sions:

May result in a short-term loss of consci­ous­ness, antero­grade amnesia (diffi­culty forming new memories), and retrograde amnesia (loss of past memories)

Loss of Speech or Language Compre­hension

Expressive Aphasia (Broca’s Aphasia):

Damage to the posterior frontal lobe (Broca’s area) affects speech produc­tion. The person unders­tands language and knows what they want to say but struggles to verbalize it, causing frustr­ation.

Global Aphasia:

Widespread damage affecting both compre­hension and speech production, severely impairing commun­ica­tion.

Quick, cost-e­ffe­ctive images of basic struct­ures, very useful as first-line assessment in emerge­ncies to identify brain issues that need emergent care (brain bleeds, etc). Uses radio

Detailed metabolic picture of brain function. Can give info about low (Alzhe­imer's, stroke­/blood vessel damaging affecting function) or high (brain tumor or other inflam­matory or cancer­-re­lated process). Uses radioa­ctive dye

Occurs after head trauma, such as a blow to the head. The person cannot recall events leading up to the injury, sometimes spanning weeks or months before the event. However, the ability to form new memories remains intact.

Caused by psycho­logical factors rather than physical brain damage. Follows different patterns from neurol­ogical disorders. Short-term memory and the ability to form new memories remain intact. Long-term autobi­ogr­aphical memory is affected, leading to loss of personal details (e.g., name, birthd­ate). Unlike neurol­ogical amnesia, where long-term memory tends to be retained.

Types of Seizures:

Genera­lized & Focal Seizures

Sudden loss of consci­ousness and stiffening (tonic activity), followed by clonic activity (rhythmic jerking). Most well-known type.

Focal Seizures (Partial Seizures):

Originate in a specific area of one hemisphere of the brain. They may or may not cause loss of awareness. (simple partial & complex partial)

Person has impaired consci­ousness or awareness. May involve staring, repetitive movements (lip-s­mac­king, hand rubbing), or confusion. The person may not remember the seizure after it ends. Often a manife­station of temporal lobe epilepsy

A type of focal seizure that originates in the primary motor cortex of the brain (part of the frontal lobe) and progresses in a charac­ter­istic pattern. Begins with localized muscle twitching (jerking movements) in a small part of the body, such as a finger, toe, or corner of the mouth. Spreads gradually to larger areas of the body (e.g., from hand → arm → face).

Reward circuits; Motor circuits involved in Parkin­son's disease; Schizo­phrenia

Depres­sion, Aggres­sion; Schizo­phrenia behavior.

Learning; Major excitatory neurot­ran­smitter in the brain

Alzhei­mer's disease

Acetyl­cho­line, due to it's role in the develo­pment of memory of the hippoc­ampus

Depression

Low serotonin and low norepi­nep­hrine

Anxiety

Too little GABA.

Autism

Too much serotonin; GABA & Glutamate imbalance

Impact on the Brain:

Can lead to brain shrinkage

Glutamate:

Profoundly out of balance

Treatment: Moderate to Severe Depression

Antide­pre­ssant medica­tions may be necessary, though it can take time to find the right one. Side effects (e.g., sexual dysfun­ction, weight gain, emotional blunting) can be a challenge

Emerging & Altern­ative Options

A non-in­vasive treatment using magnetic pulses, effective for depres­sion, OCD, and other condit­ions.

Used to manage mood swings in bipolar disorder, preventing both manic and depressive episodes

Typically used for severe cases of bipolar disorder or treatm­ent­-re­sistant depres­sion; Involves brief electrical stimul­ation of the brain while the patient is under anesth­esia. Effective for acute mood episodes but usually considered after medication and therapy have failed.

ECT involves a brief electrical stimul­ation of the brain while the patient is under anesthesia

Memory loss (retro­grade amnesia) is a signif­icant concern; Patients may experience gaps in memory from weeks to months before treatment; If ECT is repeated over time, cumulative memory loss can become disruptive

SNRI

Block serotonin & norepi­nep­hrine reuptake

TCAs

Tricyclic antide­pre­ssants affects serotonin & norepi­nep­hrine

Others

Affect serotonin/ norepi­nep­hrine in other ways

Antich­oli­nergic agents interact with many common medica­tions taken by older people