Acetylcholine (ACh) is an amine that serves as a neurotransmitter at synapses in the peripheral and central nervous systems.
Action potential
An action potential is a brief and large change in the electrical potential across the membrane of a cell. It is also called an impulse. Action potentials sweep rapidly along the length of the membrane and trigger the release of neurotransmitters.
Adenosine triphosphate (ATP)
Adenosine triphosphate (ATP) is a molecule that is important in transferring energy within cells. ATP can be converted into cAMP (cyclic adenosine monophosphate).
Attention Deficit and Hyperactivity Disorder (ADHD) is a disorder of cognition. The Diagnostic and Statistical Manual of Mental Disorders lists three subtypes: predominantly inattentive, predominantly hyperactive-impulsive, and combined type. It has a worldwide prevalence of 3-7%.
ADI is an acronym for Autism Diagnostic Interview, a clinical diagnostic instrument for assessing autism in children and adults.
Adrenaline (also known as epinephrine or adrenalin) is a catecholamine neurotransmitter and hormone. It is released by the adrenal gland and is most commonly associated with the fight or flight response to stress.
Affective flattening
Affective flattening is restriction in the range and intensity of emotional expression, expressed as an absence of emotion.
An agnosia is a perceptual impairment in the ability to recognize objects, people, sounds, shapes, smells, or tastes. Agnosias are not caused by damage to the senses, but rather by the brain's ability to process sensory information.
Alzheimer's disease
Alzheimer's disease is a degenerative disorder that progresses from memory loss to dementia, a major deterioration of cognitive function.
An an mine is an organic compound that is derived from ammonia by replacing one or more hydrogen atoms with organic groups.
Amino acid
Amino acids are the basic building blocks of protein. 20 different amino acids are commonly found in proteins.
AMPA receptor
The alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor receives glutamate at the postsynaptic cell. It is thought to be highly important to long-term potentiation.
Amphetamines are a class of drug that increase levels of dopamine as well as serotonin and norepinephrine.
The amygdala is a complex brain structure that is particularly involved in processing emotions and fear-learning.
An anion is a negatively charged ion.
In neuroanatomy, anterior (rostral) is a direction meaning toward the nose.
Aphasia is difficulty speaking or comprehending language and is associated with brain damage. The two most common aphasias are Broca's and Wernicke's.
Apoptosis is programmed cell death that is a normal part of development.
Asperger syndrome
Asperger syndrome (AS) is an early onset developmental disorder on the autistic spectrum characterized by major difficulties in social interaction, and restricted and unusual patterns of interest and behavior.
Adenosine triphosphate (ATP) is a molecule that is important in transferring energy within cells. ATP can be converted into cAMP (cyclic adenosine monophosphate).
Attention is a primary cognitive process that requires selective focusing and a filtering out of erroneous information.
Autism (or autistic disorder) is an early onset developmental disorder characterized by markedly abnormal or impaired development in social interaction and communication, and a markedly restricted repertoire of activity and interests.
Autistic spectrum disorder
Autistic spectrum disorder is the name given to the different forms and levels of what had been under the umbrella of autism, such as autistic disorder, Rett syndrome, and Asperger syndrome
Autonomic nervous system
The autonomic nervous system is the part of the nervous system that regulates automatic actions such as breathing and heartbeat.
The axon of a neuron is a long fiber extending from the cell body that transmits electrical impulses away from the neuron. At the synapse axons often communicate with dendrites.
Axon terminal
In neurons, the axon terminal is where the axon ends and (typically) communicates with the dendrites of another cell. It is also called the presynaptic terminal or the terminal bouton.