Biomaterial Database

Comparison of the behavioural effects of infusion of carbachol and acetylcholinesterase into the rat substantia nigra. 1996

C A Hawkins, and S A Greenfield

University Department of Pharmacology, Oxford, UK.

It has been postulated for many years that acetylcholinesterase (AChE) may play a nonclassical role in the substantia nigra, unrelated to its ability to hydrolyse acetylcholine. In this study the behavioural effects of unilateral infusion of AChE and a cholinergic agonist, carbachol, were compared. Carbachol induced ipsiversive circling over a very short time scale (minutes), whereas AChE induced contraversive circling, but over a longer time course-10 days. Both agents showed selectivity of response within the substantia nigra: acetylcholinesterase was only effective when infused into the most rostral region of the substantia nigra and its effects were limited to the pars compacta. In contrast, carbachol had effects in both the pars compacta and reticulata, with a graded sensitivity to carbachol in the rostral/caudal plane; infusions into rostral regions induced high rates of circling compared to more caudal areas, suggesting that the cholinergic input to the substantia nigra is not homogenous, but greater in rostral regions. This disparity between the effects of carbachol and AChE would, therefore, suggest that AChE is not exerting its long-term behavioural actions via a cholinergic mechanism, both in terms of time course of the response and the areas within the substantia nigra sensitive to these agents.

UI	MeSH Term	Description	Entries
D007267	Injections	Introduction of substances into the body using a needle and syringe.	Injectables,Injectable,Injection
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D010275	Parasympathetic Nervous System	The craniosacral division of the autonomic nervous system. The cell bodies of the parasympathetic preganglionic fibers are in brain stem nuclei and in the sacral spinal cord. They synapse in cranial autonomic ganglia or in terminal ganglia near target organs. The parasympathetic nervous system generally acts to conserve resources and restore homeostasis, often with effects reciprocal to the sympathetic nervous system.	Nervous System, Parasympathetic,Nervous Systems, Parasympathetic,Parasympathetic Nervous Systems,System, Parasympathetic Nervous,Systems, Parasympathetic Nervous
D002217	Carbachol	A slowly hydrolyzed CHOLINERGIC AGONIST that acts at both MUSCARINIC RECEPTORS and NICOTINIC RECEPTORS.	Carbamylcholine,Carbacholine,Carbamann,Carbamoylcholine,Carbastat,Carbocholine,Carboptic,Doryl,Isopto Carbachol,Jestryl,Miostat,Carbachol, Isopto
D004298	Dopamine	One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.	Hydroxytyramine,3,4-Dihydroxyphenethylamine,4-(2-Aminoethyl)-1,2-benzenediol,Dopamine Hydrochloride,Intropin,3,4 Dihydroxyphenethylamine,Hydrochloride, Dopamine
D000110	Acetylcholinesterase	An enzyme that catalyzes the hydrolysis of ACETYLCHOLINE to CHOLINE and acetate. In the CNS, this enzyme plays a role in the function of peripheral neuromuscular junctions. EC 3.1.1.7.	Acetylcholine Hydrolase,Acetylthiocholinesterase,Hydrolase, Acetylcholine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001522	Behavior, Animal	The observable response an animal makes to any situation.	Autotomy Animal,Animal Behavior,Animal Behaviors
D013239	Stereotyped Behavior	Relatively invariant mode of behavior elicited or determined by a particular situation; may be verbal, postural, or expressive.	Behavior, Stereotyped,Behaviors, Stereotyped,Stereotyped Behaviors
D013378	Substantia Nigra	The black substance in the ventral midbrain or the nucleus of cells containing the black substance. These cells produce DOPAMINE, an important neurotransmitter in regulation of the sensorimotor system and mood. The dark colored MELANIN is a by-product of dopamine synthesis.	Nigra, Substantia,Nigras, Substantia,Substantia Nigras