Drugs and Human Behavior chp 2 & 3

Neurons

Specialized cells in the nervous system that control behavior, senses, and movement

Glial Cells (or Glia Cells)

Cells that support the function of neurons

Dendrites

Parts of a neuron that receive information from other neurons

Axons

Parts of a neuron that receive information from other neurons

Synapse

Components that make up a connection between neurons that includes an axon terminal, postsynaptic terminal, and synaptic cleft

Interneuron

Neuron with the soma and axon found within the same structure

Sensory Neurons

Neuron that conveys sensory information via axons to the central nervous system

Motor Neurons

Neuron that conveys motor information via axons from the central nervous system

Oligodendrocytes

Glial cell that forms a material called myelin around the axons of neurons

Astrocytes

Glial cell that plays a role in the forming the blood-brain barrier, facilitating neuronal function and responding to injury

Microglial Cells

Glial cell that removes normal cellular waste and serves as an immune cell in the central nervous system

Gliosis

Process involving the swelling of glia cells in response to injury.

Somatic Nervous System

System responsible for delivering voluntary motor signals from the central nervous system to muscles throughout the body and for conveying sensory information from the body to the central nervous system

Autonomic Nervous System

System that controls involuntary movements for vital functions, such as heartbeat, breathing, and swallowing

Sympathetic Nervous System

System that prepares the body for rigorous activity by increasing heartbeat, inhibiting digestion, and opening airways, among many other involuntary functions

Parasympathetic Nervous System

Subsystem of the autonomic system that is dominant during relaxed states, including decreases in heartbeat, stimulation of digestion, and the closing of airways

Cerebral Cortex

The surface of the brain; comprising gyri and sulci

Medulla

Structure that controls the autonomic nervous system and is situated where the spinal cord meets the hindbrain

Hypothalamus

Structure found in the forebrain that maintains important physiological conditions, in part by motivating an organism's behavior

Limbic System

Series of structures that together appear to form a ring around the thalamus and hypothalamus

Nucleus Accumbens

Limbic system structure that facilitates reinforcing effects

Occipital Lobe

Region of the cerebral cortex important for processing visual information

Temporal Lobe

Region of the cerebral cortex important for processing auditory information and supporting language comprehension and production

Parietal Lobe

Region of the cerebral cortex important for processing touch information

Frontal Lobe

Region of the cerebral cortex important for decision making and movement

Prefrontal Cortex

Most anterior part of the frontal cortex; an integration area for all types of sensory input; initiates movements

Thalamus

Forebrain structure that routes sensory information from the body to the appropriate lobes

Motor Cortex

Part of the frontal lobe that sends movement signals to the body through the pyramidal system

Basal Ganglia

Aid in the stabilization of movement

Pons

A structure that elicits startle reflexes

Cerebellum

A structure that facilitates balance and the timing of movements

Working Memory

Consists of short-term verbal or nonverbal memories employed to carry out a task

Long-Term Memory (or Reference Memory)

Consists of stored verbal and nonverbal information

Hippocampus

A structure in the limbic system important for long-term memory

Reticular Activating System

System of structures that support arousal in the cerebral cortex

Cerebral Blood Flow

Blood flow throughout the brain

Cerebrospinal Fluid

Fluid that surrounds cells in the brain

Periaqueductal Gray

Small layer of tissue that surrounds the cerebral aqueduct

Ventricles

Cerebrospinal fluid-filled cavities in the brain

Gene

Segment of DNA encoded with the traits expressed in an organism

Polymorphism

A difference in the encoding of a gene compared to the most common sequence in a population

Transcription Factor

Substance that increases or decreases gene transcription

Epigenetics

Mechanisms of gene expression not involving alterations to DNA sequences

Neurogenetics

How genes support the function of neurons

Inhibitory Extracellular Matrix

Part of gliosis consisting of chemicals that inhibit axon growth

Neurotrophin

Naturally occurring chemical substance that promotes the growth and development of neurons

Soma

The body of a neuron.

Axon Function

The axon releases neurotransmitters to signal with other neurons.

Axon Terminal

The end of an axon that contains and releases neurotransmitters near a postsynaptic terminal.

Myelin Function

Myelin forms segments around axons and facilitates the movement of electrical impulses down the axon.

M1 Microglial Cells

Release chemicals that promote inflammation and can damage the blood-brain barrier.

M2 Microglial Cells

Release chemicals that reduce inflammation and promote cell growth and development.

Ependymocytes

Glial cells that line the ventricles and central canal and circulate cerebrospinal fluid using surface cilia.

Anterior

Directional term meaning toward the front of the brain.

Posterior

Directional term meaning toward the back of the brain.

Ventral

Directional term meaning toward the bottom of the brain.

Dorsal

Directional term meaning toward the top of the brain.

Central Nervous System

The brain and spinal cord.

Peripheral Nervous System

The part of the nervous system containing the somatic and autonomic nervous systems.

Autonomic Nervous System Additional Functions

Controls involuntary functions such as digestion and sweating by controlling heart muscle, smooth muscle, and exocrine glands.

Gyri

Hills on the surface of the brain.

Sulci

Valleys or grooves on the surface of the brain.

Medulla Additional Functions

Controls basic autonomic functions such as breathing, heart rate, and vomiting; many cranial nerves originate in the medulla.

Hypothalamus Additional Functions

Regulates body temperature, sleep, hunger, thirst, and motivation for sexual activity.

Limbic System Structures

Includes the cingulate gyrus, hippocampus, amygdala, and olfactory bulb.

Limbic System Function

Many limbic structures control emotional behavior; the amygdala facilitates fear and aggression.

Nucleus Accumbens Location

Rests adjacent and anterior to the amygdala.

Nucleus Accumbens Additional Function

Acts as the brain's reward center and belongs to a larger reward circuit.

Temporal Lobe Additional Functions

Processes certain aspects of vision, including shape and color analysis.

Parietal Lobe Additional Functions

Contains the somatosensory cortex and analyzes visual information involving movement.

Prefrontal Cortex Additional Functions

Supports short-term memory and attention.

Basal Ganglia Additional Function

Stabilizes voluntary movements.

Pons Location

Located above the medulla in the hindbrain.

Hippocampus Function

Important for long-term memory formation and retrieval.

Reticular Activating System Structures

Includes the reticular formation, tegmentum, thalamus, and hypothalamus.

Cerebrospinal Fluid Function

Provides a medium through which nutrients, glucose, hormones, and other chemicals reach brain cells.

Transgenic Animal

An animal with altered genes or additional genetic information.

Genotype

An organism's genetic makeup.

Wildtype

The typical, non-mutated version of a gene.

Knockout

An animal or gene that fails to express traits from a particular gene because the gene has been disrupted or removed.

-/- or -/+ Genotype Notation

A minus sign indicates that a gene copy has been knocked out or disrupted; in a -/+ genotype, one copy is disrupted and one normal wild-type copy remains.

Neurotransmission

Transmission of information between neurons

Electrical Transmission

Series of electrical events that begin at an axon hillock and proceed down the length of an axon

Electrical Potential

Difference between the electrical charge within a neuron versus the electrical charge of the environment immediately outside the neuron

Depolarization

Reduced difference between the positive and negative charges on each side of a membrane

Hyperpolarization

Increased difference between the positive and negative charges on each side of a membrane

Local Potential

Electrical potential on a specific part of a neuron

Ion Channels

Pores in a neuronal membrane that allow the passage of ions

Excitatory Postsynaptic Potential (EPSP)

Stimulus that depolarizes a local potential

Inhibitory Postsynaptic Potential (IPSP)

Stimulus that hyperpolarizes a local potential

Macroelectrodes

Macroelectrodes record the activity of thousands of neurons within a structure.

Microelectrodes

Microelectrodes provide a precise assessment or stimulation of either just a few or even single neurons

Intracellular Recording

The use of a microelectrode to measure potentials within a single neuron is called intracellular recording.

Microdialysis

Microdialysis procedures can be used to sample neurotransmitter levels

Resting Potential

Negatively charged local potential that precedes an action potential

Electrostatic Attraction

Attraction of ions with opposite charges

Concentration Gradient

Particles of the same type resist being concentrated

Sodium-Potassium Pump

Neuronal membrane mechanism that brings two K+ ions into the neuron while removing three Na+ ions out of the neuron

Voltage-Gated Ion Channels

Channels that open or close, depending on local potential changes

Action Potential

Rapid depolarization, causing the potential in the neuron to become temporarily more positive than the outside environment