Final Neuro Study Guide 3

Planes of dissection

Reference points used to divide the body or brain into sections for study, including sagittal, coronal, and transverse planes.

Directionality

Terms describing the position of structures relative to each other (e.g., anterior, posterior, medial, lateral, superior, inferior).

White matter

Consists of myelinated axons, allowing for communication between different brain regions.

Grey matter

Consists of neuronal cell bodies, where processing occurs.

Lobes of the cerebrum

Divided into frontal, parietal, temporal, and occipital lobes, each associated with different functions.

Cerebrum (telencephalon)

Involved in higher cognitive functions.

Diencephalon

Includes structures like the thalamus and hypothalamus, critical for sensory processing and endocrine functions.

Brainstem

Controls basic life functions such as heartbeat and breathing.

Primary cortices

Regions responsible for initial processing of sensory or motor information.

Unimodal association cortices

Areas for higher-level processing of a single type of sensory information.

Multimodal association cortices

Integrate information from multiple sensory modalities affecting complex behaviors.

Pre-frontal association cortices

Involved in executive functions, decision making, and social behavior.

Pre-motor areas

Responsible for planning and coordinating movements.

Primary motor areas

Directly involved in controlling voluntary motor movements.

Neurotransmitter release

After release, neurotransmitters bind to receptors on the postsynaptic neuron.

Neurotransmitter clearance

Termination of the signal through reuptake or degradation by enzymes.

Neurotransmitter specificity

Each neuron typically produces one neurotransmitter but can express various receptors.

Glutamate reuptake location

Occurs primarily in astrocytes surrounding the synaptic cleft.

Voltage gated ion channels

Channels that open or close in response to changes in membrane potential.

Ligand gated ion channels

Channels that open in response to neurotransmitter binding.

Postsynaptic response

Change in voltage of the postsynaptic neuron based on ion permeability.

Glutamate receptors

Includes NMDA and AMPA receptors, which are permeable to Na+ and Ca2+.

Reversal potential

Membrane potential at which there is no net flow of ions through the channel.

Reversal potential for glutamate receptors

Typically around +40 mV.

Excessive excitation effects

Can lead to seizures due to failure in glutamate clearance.

Ketamine development

Initially developed as an anesthetic, used for chronic pain before 2006.

Ketamine therapeutic range

Wider therapeutic range compared to traditional anesthetics.

Ketamine as a dirty drug

Effects multiple receptor systems, complicating its classification.

Major receptor target of ketamine

NMDA receptor, where it acts as a use-dependent blocker.

Full agonist

Activates the receptor fully to produce a maximal response.

Partial agonist

Activates the receptor but produces a less than maximal response.

Antagonist

Blocks the receptor and prevents activation.

Reverse agonist

Produces opposite effects of an agonist upon binding.

Disinhibition in ketamine

Refers to different behavioral effects based on dosage.

GABA synthesis

Derived from glutamate through the action of glutamic acid decarboxylase.

GABA reuptake location

Occurs in the presynaptic neuron and surrounding glial cells.

Types of GABA receptors

GABAA (ionotropic) and GABAB (metabotropic); GABAA is permeable to Cl-.

Reversal potential for GABAA receptors

Typically around -70 to -90 mV, leading to hyperpolarization.

Benzodiazepines

Enhance GABA effects; preferred due to a safer profile than barbiturates.

Withdrawal effects from benzodiazepines

Caused by bodily adaptation leading to increased receptor sensitivity.