Locomotor

Hyperalgesisa, later hypoalgesia Lethargy, somnolence Anorexia, adipsia Weakness, malaise Decreased locomotor activity Inability to concentrate... 

According to the NC-IUPHAR Subcommittee on Opioid Receptois it was proposed to term ORL-1 recqrtor as NOP receptor [1]. The human NOP receptor gene encodes a protein of370 amino acids. Splice valiants have been found in the human and mouse NOP recqrtor with no known functional significance. NOP receptors are widely distributed throughout the brain and in the spinal cord. They are also present in immune cells. A functional role for N/OFQ has been proposed in nociception, locomotoric activity, reward, stress, and immunomodulation. 

Dopaminergic mechanisms within the ventral striatum (i.e., nucleus accumbens) subserve the ability of amphetamine and methylphenidate in low to moderate doses to increase locomotor activity. In contrast, very low dosages in animals seem to cause hypoactivity presumably by stimulation of autoreceptors, a finding that would be compatible with the clinical impression that methylphenidate might be usefiil in some patients with mania. 

The characteristic behavioral effects of acute and chronic psychomotor stimulant diugs are locomotor activation, stereotypy, and conditioned reward and stimulus-reward learning. The most important brain regions involved in these effects are summarized in Table 3. 

Other brain regions Effects on cognitive, locomotor, sensory and autonomic functions, analgesic effects... 

Wilkinson, P.C. (1986). The locomotor capacity of human lymphocytes and its enhancement by cell growth. Immunology 57, 281-289. 

There are few reports on the effects of nitrous oxide on dopaminergic neurotransmission. A study in mice showed that nitrous oxide inhalation produced a significant increase in locomotor activity that was antagonized in a dose-dependent fashion by the dopamine synthesis inhibitor a-methyl-/)-tyrosine (Hynes and Berkowitz 1983). Moreover, administration of the D2 antagonist haloperidol also reduced the locomotor activity induced by nitrous oxide (Hynes and Berkowitz 1983). These results suggest that excitatory effects induced by nitrous oxide may be also mediated by dopaminergic neurotransmission. However, other studies have reported that exposure to nitrous oxide resulted in decreased dopamine release by neurons in the striatum (Balon et al. 2002 Turle et al. 1998). 

There are similarities between the biological actions of inhalants and those of alcohol and barbiturates (Bowen et al. 1996b). For example, acute administration of inhalants affects motor coordination (Moser and Balster 1981) and induces anxiolysis, whereas chronic administration is associated with physical dependence and withdrawal (Bowen et al. 1996a Evans and Balster 1991, 1993). In addition, some inhalant drugs have anticonvulsant properties (Wood et al. 1984). Like other CNS-depressant agents, inhalants have biphasic effects on spontaneous locomotor activity in rodents, with increased activity seen at lower doses and diminished locomotion seen at higher doses (Cause et al. 1985 Kjellstrand et al. 1985). 

Bowen SE, Balster RL A direct comparison of inhalant effects on locomotor activity and schedule-controlled behavior in mice. Exp Clin Psychopharmacol 6 235— 247, 1998... 

Bredt DS, Snyder SEl Nitric oxide, a novel neuronal messenger. Neuron 8 3—11, 1992 Brouette T, Anton R Clinical review of inhalants. Am J Addict 10 79-94, 2001 Brown ES, Nejtek VA, Perantie DC, et al Quetiapine in bipolar disorder and cocaine dependence. Bipolar Disord4 406 11, 2002 Bushnell PJ, Evans EIL, Palmes ED Effects of toluene inhalation on carbon dioxide production and locomotor activity in mice. Fundam Appl Toxicol 5 971-977, 1983... 

Himnan DJ Tolerance and reverse tolerance to toluene inhalation effects on open-field behavior. Pharmacol Biochem Behav 21 625-631, 1984 Hinman DJ Biphasic dose-response relationship for effects of toluene inhalation on locomotor activity. Pharmacol Biochem Behav 26 65-69, 1987 Hormes JT, Filley CM, Rosenberg NL Neurologic sequelae of chronic solvent vapor abuse. Neurology 36 698—702, 1986... 

Hynes MD, Berkowitz BA Catecholamine mechanisms in the stimulation of mouse locomotor activity hy nitrous oxide and morphine. Eur J Pharmacol 90 109-114, 1983... 

Riegel AC, French ED Acute toluene induces biphasic changes in rat spontaneous locomotor activity which are blocked by remoxipride. Pharmacol Biochem Behav 62 399-402, 1999... 

Engenheiro, E.L., Hankard, P.K., and Sousa, J.P. et al. (2005). Influence of dimethoate on acetylcholinesterase activity and locomotor function in terrestrial isopods. Environmental Toxicology and Chemistry 24, 603-609. 

Invertebrate prey species contain analogous, but not identical, sites to those considered above. In many phylla, calcium channels play the role normally ascribed to sodium channels in vertebrates. In addition, the peripheral locomotor neurotransmitter is not acetylcholine but amino acids such as gamma amino butyric acid (GABA). In other phylla, the channels which underly locomotion remain poorly understood. 

Taylor DH, Lagory KE, Zaccaro DJ, et al. 1985. Effect of trichloroethylene on the exploratory and locomotor activity of rats exposed during development. Sci Total Environ 47 415-420. 

Initiation of behaviour Mesolimbic pathway to nucleus accumbens from VTA (AIO) Mesocortical pathways to prefrontal cortex from VTA (AIO) Animals Increases locomotor activity and intracranial self-stimulation Humans Hallucinations, psychoses (reward, reinforcement) Animals Decreases activity and self-stimulation Humans Reduces positive symptoms of schizophrenia D2 ... 

As far as can be certain, given the lack of selective ligands, their aetivation elsewhere in the brain is thought to culminate in reduced locomotor activity and hyperthermia. However, interest in these reeeptors as possible therapeutie targets is fostered by evidence that their agonists, sueh as mCPP, appear to be profoundly anxiogenic (see Chapter 19) and reduce food intake (see below). 

Krebs-Thomson, K, Paulus, MP and Geyer, MA (1998) Effects of hallucinogens on locomotor and investigatory activity and patterns influence of 5-HT2A and 5-HT2C receptors. Neuropsychopharmacology 18 339-351. 

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