Biological Basis of Behavior 2 Exam 1 review

Information → Behavior

Sensory neurons → CNS → processing → motor neurons → muscles

Major brain divisions: FOREBRAIN

Telencephalon, Diencephalon

Major brain divisions: MIDBRAIN

Mesencephalon

Major brain divisions: HINDBRAIN

Metencephalon, Myelencephalon

Metencephalon contains

pons and cerebellum

Myelencephalon contains the

Medulla

Four lobes of the Cerebral Cortex

Frontal • Parietal • Temporal • Occipital

Planning and organization of movement

frontal lobe

Direct control of voluntary movement

Primary motor cortex

Areas that are not primarily concerned with sensation or movement

Association cortex

Membrane Potential

Difference in electrical charge between the inside and outside of the

neuronal membrane.

Depolerization

Becoming less negative / closer to 0. −72 mV → −60 mV

hyperpolorization

Becoming more negative / farther from 0 ,−65 mV → −82 mV

Examples of important ions

Na⁺, K⁺, Cl⁻, Ca²⁺

Ion channels

Specialized protein molecules in the membrane that open or close to control the movement of ions

Rate Law

Stimulus intensity is represented mainly by: the firing rate of action potentials

synaptic vesticles

contain neurotransmitters

Excitatory postsynaptic potential (EPSP)

Membrane becomes LESS negative, Postsynaptic Potentials are MORE likely to fire. produces depolerization

Inhibitory postsynaptic potential (IPSP)

Membrane becomes MORE negative, Postsynaptic Potentials are LESS likely to fire. produces hyperpolerization

Glutamate

The primary excitatory neurotransmitter in the CNS is commonly associated with EPSP

GABA

Primary inhibitory neurotransmitter in the CNS commonly associated with IPSP

Autonomic Nervous System (ANS)

Part of the peripheral nervous system. Two major divisions: sympathetic (“Fight or flight”) and parasympathetic (“Rest and digest”)

Learning

The process by which experience changes the nervous system and behavior, and allows us to acquire new information. depends on brain plasticity

Memory

Relatively lasting changes in the nervous system following learning. depends on brain plasticity

Stimulus–Response Learning

Learning a particular response in response to a stimulus. (how to respond to stimulus)

Motor Learning

Learning a new motor response or sequence ( how to do actions)

Perceptual Learning

Learning to recognize previously experienced stimuli. (how to recognize something)

Relational Learning

Learning relate among multiple stimuli. (how TWO OR MORE things relate to one another)

Classical Conditioning

A type of stimulus-response learning. Association between stimuli

Instrumental / Operant Conditioning

A type of stimulus-response learning. Behavior is influenced by consequences. Through experience, connections strengthen between:

Conditioned Emotional Response

Information about the:

Conditioned stimulus (CS) + Unconditioned stimulus (US)

↓

converges in the

lateral nucleus of the amygdala

↓

projects to the central nucleus

↓

Emotional/behavioral response

lateral nucleus

Learning/ Linking Nucleus

central nucleus

carries out the response

As responses become well learned and more automatic

basal ganglia become especially important

Visual Processing

Dorsal stream = “ Where” spatial location

Ventral stream = “ What” object identification

Perceptual Learning

Learning to recognize or categorize previously experienced stimuli. Primarily involves the sensory association cortex

Sensory association cortex

 Visual recognition and Auditory recognition

Motor Learning

Involves: Changes within the motor

systems/pathways

● Sensory guidance from the environment

● Cortex + basal ganglia

Practice + consolidation

can improve later performance

Relational Learning

Learning the relation among individual stimuli

Includes: Spatial relationships, Sequences, Context/relationships among events

Major brain structure: Hippocampus

Morris Water Maze

Goal: locate a hidden platform using environmental cues.

Same starting point:

An animal may learn a particular response/ route

Different starting points:

Must use relationships among environmental cues

→ relational learning

Short-Term Memory

Retains information for approximately a few seconds

Declarative / Explicit Memory

Facts and events

Nondeclarative / Implicit Memory

 Skills and learned responses (habits)

Episodic Memory

Memory for personally experienced events in context (type of declarative memory)

Memory Consolidation

New memories are initially relatively unstable. Over time, neural changes help make those memories more stable. A major brain region involved in processing newly acquired information:

hippocampus/ hippocampal formation

Patient H.M.

Severe difficulty forming new long-term declarative memories. This pattern is called anterograde amnesia

Long-Term Potentiation (LTP)

After repeated high-frequency activity, a synapse shows lasting increases in responsiveness.

After LTP:

Same input → larger postsynaptic response

LTP is commonly studied in hippocampus circuits.

AMPA receptors

Glutamate receptors. Activation allows positive ions to enter, helping produce depolarization of the postsynaptic membrane

NMDA receptors

Glutamate receptor. Requires glutamate AND sufficient depolarization. At resting membrane potential, the channel is occupied by Mg²⁺. Becomes active after the AMPA receptors help depolarize

NMDA RECEPTOR & CALCIUM ENTRY

At resting membrane potential:

NMDA channel contains a Mg²⁺ block

↓

Ca²⁺ entry is limited

With glutamate + sufficient depolarization:

Mg²⁺ is displaced

↓

NMDA channel opens

↓

Calcium enters the dendritic spine

NMDA requires BOTH: Glutamate + Depolarization

CALCIUM → INCREASED AMPA RESPONSIVENESS

Calcium → Stronger Synapse

Ca²⁺ enters through NMDA receptors

↓

Activates intracellular signaling

↓

Increases AMPA receptor availability at the postsynaptic membrane

↓

The same glutamate input produces a stronger EPSP

Result: The synapse becomes more responsive/stronger

LASTING CHANGES IN LTP

Longer-lasting synaptic strengthening can involve: Remodeling of dendritic spines, Changes in synaptic structure and connectivity, and Molecular changes requiring new protein production

ASSOCIATIVE LTP

Sometimes, a weak pathway is not strong enough by itself to produce LTP.

The timing of activity across pathways matters.

A weak pathway is active alone

→ may be insufficient for LTP

Coincident activity across pathways

→ greater postsynaptic depolarization

→ NMDA activation + Ca²⁺ entry

→ active connections can become stronger