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Term Definition
NaloxoneA short-acting opiate antagonist that binds to opiate receptors and blocks them, preventing opiates from binding to these receptors. Naloxone is used to treat opiate overdoses.

NaltrexoneA long-lasting opiate antagonist used for the treatment of heroin addiction, and more recently used for the treatment of alcohol addiction.

negative reinforcementReward generated by the removal of painful or stressful conditions or events.

Nembutal(pentobarbital) A depressant drug of the barbiturate family used to induce sleep.

neural substrateThe set of brain structures that underlies specific behaviors or psychological states.

neurochemicalsNeurotransmitters and other brain chemicals produced by neurons.

neuronNerve cell. Neurons are unique cells found in the brain and body that are specialized to process and transmit information.

neuroscienceThe study of how the brain and nervous system work. Neuroscience integrates more traditional scientific approaches such as anatomy, physiology, and biochemistry, along with newer fields such as molecular biology and computer science, to understand how the nervous system functions.

neurotoxinsSubstances that damage or kill neurons.

neurotransmissionThe process that occurs when a neuron releases neurotransmitters to communicate with another neuron across the synapse.

neurotransmitterChemicals produced by neurons to carry their messages to other neurons.

NicotineThe drug in tobacco that is addictive. Nicotine also activates a specific kind of acetylcholine receptor.

nicotinic cholinergic receptorOne of two acetylcholine receptors. This one responds to nicotine as well as acetylcholine.

Nitrous OxideAn inhalant, also known as "laughing gas." Nitrous oxide is a weak anesthetic that does not produce unconsciousness.

norepinephrineA neurotransmitter and a hormone. It is released by the sympathetic nervous system onto the heart, blood vessels, and other organs and by the adrenal gland into the bloodstream as part of the fight-or-flight response. Norepinephrine is also present in the brain and is used as a neurotransmitter in normal brain processes.

nucleusA cluster or group of nerve cells that is dedicated to performing its own special function(s). Nuclei are found in all parts of the brain except the cerebral cortex, where such groups are called cortical fields.

nucleus accumbensA part of the brain reward system, located in the limbic system, that processes information related to motivation and reward. It is the key brain site where virtually all drugs of abuse act to reinforce drug taking.

Special Thanks:
Addiction Studies Program - Wake Forest University School of Medicine
False Messengers: How Addictive Drugs Change the Brain by David Friedman, PhD, and Sue Rusche, Harwood Academic Publishers, Amsterdam, The Netherlands, 1999. [www.addictionstudies.org]