| motor neuron | Synonym for motoneuron. (18 Nov 1997) |
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| motor neuron disease | <disease> Degenerative disease of unknown cause that affects predominantly motor neurons of spinal cord, cranial nerve nuclei and motor cortex. There is speculation that deficiency in ciliary neurotrophic factor may be involved. (18 Nov 1997) |
| multipolar neuron | A neuron with several processes, usually an axon and three or more dendrites. (05 Mar 2000) |
| polymorphic neuron | Occurring in many shapes. See: multipolar cell. (05 Mar 2000) |
| postganglionic motor neuron | See: motor neuron. (05 Mar 2000) |
| preganglionic motor neuron | See: motor neuron. (05 Mar 2000) |
| pseudounipolar neuron | A neuron whose cell body emits a single axonal process resulting from the fusion of two polar processes during development; at a variable distance from the cell body, the process divides into a peripheral axon branch extending outward as a peripheral afferent (sensory) nerve fibre, and a central axon branch that enters into synaptic contact with neuron's in the spinal cord or brainstem. With the single known exception of the neuron's composing the mesencephalic nucleus of the trigeminus, unipolar neuron's are the exclusive neural elements of the sensory ganglia. The lack of dendritic processes of these primary sensory neuron's is only apparent: the dendritic pole of the unipolar neuron is represented by the unmyelinated terminal ramifications of the peripheral axon branch. Synonym: pseudounipolar cell, pseudounipolar neuron, unipolar cell. (05 Mar 2000) |
| sensory neuron | 1. <anatomy> A neuron that receives input from sensory cells. 2. <physiology> Sensory cells such as cutaneous mechanoreceptors and muscle receptors. (18 Nov 1997) |
| somatic motor neuron | See: motor neuron. (05 Mar 2000) |
| NANC neuron | <abbreviation> Nonadrenergic, noncholinergic neuron. (05 Mar 2000) |
| neuron | An excitable cell specialised for the transmission of electrical signals over long distances. Neurons receive input from sensory cells or other neurons and send output to muscles or other neurons. Neurons with sensory input are called sensory neurons, neurons with muscle outputs are called motoneurons, neurons that connect only with other neurons are called interneurons. Neurons connect with each other via synapses. Neurons can be the longest cells known, a single axon can be several metres in length. Although signals are usually sent via action potentials, some neurons are nonspiking. (18 Nov 1997) |
| nonadrenergic, noncholinergic neuron | Autonomic efferent neuron whose transmission is not blocked by blocking adrenergic and cholinergic transmission. Nitric oxide may be the transmitter in some cases. (05 Mar 2000) |
| nonspiking neuron | <physiology> A neuron that can convey information without generating action potentials. As passive electrical potentials are attenuated over distances greater than the space constant for a neuron (typically 1mm), this implies that most nonspiking neurons are involved in signalling over relatively short distances. Typical examples are invertebrate stretch receptors and interneurons in the central nervous system. (12 Mar 1998) |
| intercalary neuron | A neuron interposed between and connecting two other neuron's. Synonym: intercalary neuron. (05 Mar 2000) |
| internuncial neuron | A neuron interposed between and connecting two other neuron's. Synonym: intercalary neuron. (05 Mar 2000) |