Cellular Function, Neurotransmission, and Pharmacology

Flashcards covering key terms and concepts from Chapter 2 on Cellular Function, Neurotransmission, and Pharmacology.

Cell Membrane Membrane Bilayer

A semipermeable membrane encasing the cell body, consisting of a double layer of lipid molecules with hydrophilic heads and hydrophobic tails.

Rough Endoplasmic Reticulum

Organelle studded with ribosomes that produce proteins destined for transport inside and outside the cell.

Smooth Endoplasmic Reticulum

Organelle responsible for producing lipids and transporting proteins to the Golgi apparatus.

Golgi Apparatus

Organelle that assembles proteins and packages them into vesicles to be sent to other cellular destinations.

Mitochondria

Organelles that supply cellular energy by producing Adenosine Triphosphate (ATP).

Cytoskeleton

Internal structural framework of a cell maintained by protein strands, including actin filaments and microtubules.

Anterograde Transport

Movement of substances and organelles by specialized proteins through microtubules from the cell body to the terminal button.

Retrograde Transport

Movement of substances and organelles by specialized proteins through microtubules from the terminal button to the cell body.

Synapse

The functional contact site where an axon communicates with its target cell.

Presynaptic Neuron

The neuron that sends a chemical signal via neurotransmitter release into the synaptic cleft.

Postsynaptic Neuron

The neuron that receives chemical signals via neurotransmitter receptors.

Dendritic Spine

A small protuberance on a dendrite that contains receptors for binding neurotransmitters.

Terminal Button

A bulbous structure located at the end of an axon from which neurotransmitters are released.

Diffusion

The passive movement of ions from an area of higher concentration to an area of lower concentration along a concentration gradient.

Electrostatic Pressure

The force driving ions toward oppositely charged areas due to attraction between opposite charges and repulsion between like charges.

Resting Potential

The electrical potential of a neuron when it is not actively communicating, where the inside of the cell is negatively charged ($-70\,\text{mV}$) relative to the outside.

Sodium-Potassium Pump

A membrane mechanism that maintains resting potential by active transport, pumping three $\text{Na}^+$ ions out of the cell for every two $\text{K}^+$ ions pumped in.

Nodes of Ranvier

Unmyelinated gaps along an axon's insulating myelin sheath where action potentials are regenerated.

Saltatory Conduction

The rapid propagation of an action potential along a myelinated axon, where the electrical signal jumps from node to node.

Autoreceptor

A presynaptic receptor that binds its own neuron's released neurotransmitter to provide feedback inhibition, regulate synthesis and release, and maintain homeostasis.

Ionotropic Receptors

Postsynaptic receptor channels that directly open upon ligand binding, producing rapid and shorter-lasting electrical effects.

Metabotropic Receptors

G-protein coupled receptors that initiate intracellular secondary messenger signaling cascades, producing slower and longer-lasting cellular effects.

Reuptake

The process of removing neurotransmitter molecules from the synaptic cleft via specialized protein transporters on the presynaptic membrane or astrocytes.

Enzymatic Deactivation

The degradation of neurotransmitter molecules by specific enzymes while they remain in the synaptic cleft.

Endogenous Ligands

Naturally occurring internal substances, such as neurotransmitters and hormones, that bind to and activate or block receptors.

Exogenous Ligands

Substances originating outside the body, such as drugs and toxins, that bind to body receptors.

Agonist

A ligand or drug that binds to a receptor and initiates its normal biological action.

Antagonist

A ligand or drug that binds to a receptor and prevents or blocks its activation by other ligands.

Nitric Oxide

A transmitter gas involved in dilating cerebral blood vessels, hypothesized to play a role in learning and memory.

Oxytocin

A peptide neurotransmitter/hormone that exerts modulatory effects on pain perception.

Vasopressin

A peptide neurotransmitter believed to participate in facial processing and social responses in humans.

Aspartate

An excitatory amino acid neurotransmitter closely related to glutamate that depolarizes neuronal membranes.

Glutamate

The primary excitatory amino acid neurotransmitter in the brain, accounting for $50\%$ of synapses and critical for learning and memory.

Gamma-Aminobutyric Acid (GABA)

The main inhibitory amino acid neurotransmitter, present in $30\%$ of synapses, with receptor subtypes $\text{GABA}_A$, $\text{GABA}_B$, and $\text{GABA}_C$.

Dopamine

A catecholamine monoamine neurotransmitter concentrated in the basal ganglia, substantia nigra, and tegmentum, involved in movement, attention, motivation, and learning.

Norepinephrine

A catecholamine monoamine biosynthesized in terminal vesicles from dopamine, primarily originating from cell bodies in the locus coeruleus.

Adrenaline

A catecholamine monoamine neurotransmitter involved in initiating the 'fight or flight' stress response.

Serotonin (5-HT)

An indolamine monoamine neurotransmitter concentrated in the brain stem that regulates arousal, wakefulness, sleep, and appetite.

Acetylcholine (ACh)

A neurotransmitter active throughout the central and peripheral nervous systems acting on ionotropic nicotinic and metabotropic muscarinic receptors, implicated in attention, memory, and learning.

Psychopharmacology

The scientific study of chemical compounds that selectively alter function within the nervous system.

Psychotropic Medications

Pharmacological agents prescribed to manage cognitive and behavioral symptoms associated with psychiatric disorders.