Acetylcholine or ACh- Neurotransmitter released into the synaptic cleft from certain neurons of the brain and autonomic nervous systems; a white crystalline derivative of choline, its chemical formula is C7H17NO3.
Affinity- The strength of noncovalent chemical binding between two substances as measured by the dissociation constant of the complex. (Basically, the tendency for a chemical to bind to a receptor.)
Agonist- A substance which mimicks physiologic activity of the brain's natural neurotransmitters at cell receptors
Alzheimer's Disease- A progressive, neurodegenerative disease characterised by loss of function and death of nerve cells in several areas of the brain leading to loss of cognitive function such as attention, memory, and language. The cause of nerve cell death is unknown but the cells are recognised by the appearance of unusual helical protein filaments in the nerve cells (neurofibrillary tangles) and by degeneration in cortical regions of brain, especially frontal and temporal lobes. Alzheimer's disease is the most common cause of dementia.
Amygdala- Meaning almond in Latin, this region of the brain is part of the limbic system, and is implicated in many psychiatric disorders such as schizophrenia and Post Traumatic Stress Disorder (PTSD).
Antagonist- A substance which interferes with the functions of the brain's natural neurotransmitters
Attention- A psychological construct describing detection, selection, discrimination of stimuli, as well as allocating of limited processing resources to competing attentional demands. Functional attentional processing is essential for higher order cognitive processes such as learning and memory.
Basal Forebrain Cortical Cholinergic System (BFCS)- A neural network necessary for attentional processing; the basal forebrain is a functional neighborhood of nuclei (septum, diagonal band of Broca, and nucleus basalis). that sends cholinergic projections to hippocampus and neocortex.
Central Nervous System- Consisting of the spinal cord and brain, it is the centre of thought and emotion. It is responsible for the coordination and control of bodily activities and the interpretation of information from the senses (sight, hearing, smell, etc.).
Cerebrospinal Fluid (CSF)- A clear, colourless fluid that contains small quantities of glucose and protein. Cerebrospinal fluid fills the ventricles of the brain and the central canal of the spinal cord as well as the spaces between nerve cells.
Cerebral Cortex- The outer portion of the brain, consisting of layers of nerve cells and the pathways that connect them. The cerebral cortex is the part of the brain in which thought processes take place. In Alzheimer's disease, nerve cells in the cerebral cortex die.
D-CPP- Glutamate antagonist (Blocks NMDA receptors)
Dopamine- A monoamine catecholamine neurotransmitter and hormone (C8H11NO2) which is a precursor of norepinephrine. It is involved in motor activity, reward, learning, memory, and various other functions.
Drug Addiction- A monopolization of the attentional system by drug-related stimuli. For example, if cocaine addicts see white powder, they will probably experience cravings, because their brain associates white powder with cocaine.
Excitatory- Exerting stimulating effects
Glutamate- A salt or ester of glutamic acid, functioning as a neurotransmitter that excites cells of the central nervous system.
Hippocampus- a complex neural structure (shaped like a sea horse) consisting of gray matter and located on the floor of each lateral ventricle; intimately involved in motivation and emotion as part of the limbic system; has a central role in the formation of memories
Inhibitory- Exerting dampening effects
Input- Inflow of information
Ligand- A soluble molecule such as a hormone or a neurotransmitter which binds to a receptor
Limbic System- A group of deep brain structures, common to all mammals and including the hippocampus, amygdala, gyrus fornicatus, hypothalamus and connecting structures, associated with olfaction, emotion, motivation, behavior, and various autonomic functions.
Modulation- Regulating information flow
Neurotransmitter- A chemical substance, such as acetylcholine or dopamine, that transmits nerve impulses across a synapse.
Neuron- Any of the impulse-conducting cells that constitute the brain, spinal column, and nerves, consisting of a nucleated cell body with one or more dendrites and a single axon. Also called a nerve cell.
NMDA- A synthetic amino acid (C5H9NO4) that binds selectively to a subset of glutamate receptors on neurons where the binding of glutamate results in the opening of calcium channels. Also called N-methyl-D-aspartate.
Nucleus Accumbens- A part of the brain reward system, located in the limbic system, is involved in motivation and reward. It is the key brain site where virtually all drugs of abuse act to reinforce drug taking.
Prefontal Cortex- The rostral part of the frontal lobe, bounded by the inferior precentral fissure in humans, which receives projection fibres from the mediodorsal nucleus of the thalamus. The prefrontal cortex receives afferent fibres from numerous structures of the diencephalon, mesencephalon, and limbic system as well as cortical afferents of visual, auditory, and somatic origin.
Receptor- A molecular structure or site on the surface or interior of a cell that binds with substances such as hormones, antigens, drugs, or neurotransmitters; the intermediary between a chemical agent (as a neurohormone) acting on nervous tissue and the physiological or pharmacological response.
Schizophrenia- Any of a group of psychotic disorders usually characterized by withdrawal from reality, illogical patterns of thinking, delusions, and hallucinations, and accompanied in varying degrees by other emotional, behavioral, or intellectual disturbances. Schizophrenia is associated with dopamine imbalances in the brain and defects of the frontal lobe and is caused by genetic, other biological, and psychosocial factors. It is mainly treated by antipsychotic drugs which block Dopamine receptors such as Haloperidol.
Synapse- The junction across which a nerve impulse passes from an axon terminal to a neuron, muscle cell, or gland cell.
Top-Down Processing- The cortex gives feedback and modulates the subcortical areas.