Neurological Foundation of New Zealand

A

• Abducens nerve

  Cranial nerve VI - innervates the lateral rectus muscle of the eye. It is the only cranial nerve that originates from the dorsal surface of the brainstem.

• Ablation

  Removal or destruction of tissue.

• Acetylcholine (ACh)

  A neurotransmitter found in the brain, spinal cord, neuromuscular junction and autonomic nervous system.

• Acetylcholinesterase (AChE)

  Enzyme that terminates the action of acetylcholine.

• Action potential

  Electrical 'all-or-none' impulse that transmits information within the nervous system.

• Adrenergic

  Associated with catecholamines.

• Afferent

  Neural information flowing from the periphery to more central areas of the nervous system.

• Agonist

  Chemical that acts like a neurotransmitter; increases the effect of a neurotransmitter.

• Alzheimer's disease

  A degenerative brain disease. Characterised by memory loss and disorientation.

• Amnesia

  Partial or complete loss of memory. 'Anterograde' amnesia is when people cannot form new memories.

• Amphetamine

  A synthetic central nervous system stimulant.

• Amplitude

  The size or magnitude of a signal or response.

• Amygdala

  Brain structure that is part of the limbic system. Implicated in emotion.

• Analgesia

  Insensitivity to pain.

• Antagonist

  Chemical that blocks the action of a neurotransmitter

• Anterior

  A directional term meaning toward the front.

• Anterior commissure

  A small fibre tract that connects the right and left cerebral hemispheres (like the corpus callosum).

• Aphasia

  Inability to speak or understand language.

• Aqueous humor

  Fluid in the space between the cornea and lens of the eye.

• Arachnoid

  Middle layer of the meninges.

• Astrocyte (astroglia)

  A glial cell that supports neurons.

• Autoradiography

  Neuroanatomical method using radioactivity that is incorporated into neurons.

• Axodendritic (synapse)

  A synapse formed by contact between a presynaptic axon and a postsynaptic dendrite.

• Axon

  The part of the neuron that takes information AWAY from the cell body.

B

• Basal Ganglia

  Areas of the brain that are important for movement. These areas include the putamen, caudate nucleus, globus pallidus, subthalamic nucleus and substantia nigra.

• Bipolar neuron

  Neuron with only two processes extending from the cell body.

• Blood brain barrier

  A system of astrocytes and capillaries in the brain that prevents the passage of specific substances.

• Brainstem

  The central core of the brain.

C

• Cauda equina

  The 'horse's tail' made up of a bundle of spinal nerves at the base of the spinal cord.

• Caudal

  A directional term meaning toward the tail end.

• Cell body

  Also called the soma; the part of the cell that contains the nucleus.

• Central Nervous System (CNS)

  The brain and spinal cord.

• Central sulcus

  Large groove in the brain that separates the frontal and parietal lobes.

• Cerebellum

  Area of the brain above the pons and medulla that is important for balance and posture.

• Cerebral aqueduct

  Part of the ventricular system that connects the third and fourth ventricles.

• Cerebral cortex

  Outermost layer (the gray matter) of the cerebral hemisphere.

• Cerebrospinal fluid (CSF)

  Clear fluid in the ventricular system.

• Chimeric figure

  Figure using two separate faces on each half. These figures are used in split brain experiments.

• Choroid plexus

  Vascular structures in the ventricular system that produce cerebrospinal fluid.

• Cingulate cortex

  Part of the limbic system. Located directly above the corpus callosum. Important for emotional behavior.

• Circadian

  About one day; used to describe some body rhythms.

• Cochlea

  Inner ear structure important for hearing.

• Cone

  Receptor found in the retina important for colour vision and detailed sight.

• Cornea

  Transparent front coat of the eye.

• Corpus callosum

  Large collection of axons that connect the left and right hemispheres of the brain.

• Cranial nerves

  12 pairs of nerves that exit from the brain.

• Cranium

  The part of the skull that contains the brain.

D

• Dendrite

  Extensions from the neuron cell body that take information TO the cell body.

• Depolarisation

  Movement of the membrane potential toward 0 mV; a decrease in polarisation.

• Dopamine

  A neurotransmitter found in many areas of the brain. Important for movement and other behaviour.

• Dorsal root

  Bundle of nerve fibres taking information into the spinal cord.

• Dura

  Outermost layer of the meninges.

E

• Electroencephalogram (EEG)

  Record of electrical activity of the brain obtained from scalp electrodes.

• Endorphin

  Neurotransmitter with similar properties as opiates. Important for pain reduction.

• Excitatory Postsynaptic Potential (EPSP)

  A graded depolarisation of the postsynaptic cell.

F

• Fetal Alcohol Syndrome

  When a foetus is exposed to alcohol and consequently develops a pattern of unusual facial features and impaired brain development

• Fornix

  Pathway that connects the hippocampus with the mamillary bodies.

• Fovea

  Central part of retina; area of retina with most accurate vision.

G

• Glia

  Non-neural support cells of the nervous system.

• Gyrus (plural is gyri)

  'Hills' or 'bumps' on the brain that are separated by fissures.

H

• Hippocampus

  Area of the limbic system important for memory.

• Hormones

  Chemicals used by endocrine system to transmit messages.

• Hypothalamus

  Brain structure that monitors internal environment and attempts to maintain balance of these systems. Controls the pituitary.

I

• Inferior colliculus

  Midbrain structure important for hearing.

• Iris

  Muscles of eye that control the size of the pupil. Gives color to the eye.

L

• Lens

  Transparent structure in the eye that focuses light on the retina.

• Lesion

  Injury caused by destruction of tissue.

• Limbic system (or Limbic areas)

  Interconnected areas of the brain important for emotional and other behaviours.

M

• Medulla

  Part of the brain stem important for breathing, respiration and other behaviours.

• Meninges

  Series of three membranes (dura mater, arachnoid, pia mater) that cover the brain and spinal cord.

• Myelin sheath

  Fatty substance that surrounds some axons.

N

• Neurotransmitters

  Chemicals that transmit information across the synapse to communicate from one neuron to another.

• Node of Ranvier

  Short unmyelinated segment of an axon.

O

• Occipital lobe

  Area of the brain located behind the parietal lobe and temporal lobe and responsible for vision.

• Optic chiasm

  Crossing of the fibers from each retina.

• Ossicles

  Bones in the middle ear.

P

• Parkinson's disease

  Neurological disorder caused by damage to the dopamine system of the brain; symptoms include tremor, rigidity, slow movement.

• Pia

  Inner most layer of the meninges. Adjacent to the surface of the brain.

• Pituitary

  'Master' gland attached to the base of the brain that secretes hormones.

• Pons

  Area of the brainstem between the medulla and the midbrain.

• Proprioceptor

  Sensory receptor providing information related to body position, mainly in muscles and tendons.

R

• Retina

  Innermost layer of the eye; contains receptors responsive to light.

• Rod

  Receptor found in the retina important for in low light conditions.

S

• Soma

  The neuron cell body. Contains the nucleus.

• Sulcus (plural is sulci)

  Groove located on the surface of the brain.

• Synapse

  Functional connection between a terminal of one neuron with a membrane of another neuron.

T

• Tectum

  "Roof" of the midbrain.

• Tegmentum

  "Floor" of the midbrain.

• Thalamus

  Group of nuclei in the diencephalon of the brain. The different nuclei have sensory and motor functions.

V

• Ventricles

  Hollow spaces within the brain that are filled with cerebrospinal fluid.