Interpeduncular nucleus

Three tachykinin GPCRs, NK, NK, and NK, have been identified and cloned. AH are coupled to phosphatidjhnositol hydrolysis. The NK receptor is selective for substance P (SP) and is relatively abundant in the brain, spinal cord, and peripheral tissues. The NK receptor is selective for NKA and is present in the gastrointestinal tract, urinary bladder, and adrenal gland but is low or absent in the CNS. The NIC receptor is selective for NKB and is present in low amounts in the gastrointestinal tract and urinary bladder, but is abundant in some areas of the CNS, ie, the spinal dorsal bom, soUtary nucleus, and laminae IV and V of the cortex with moderate amounts in the interpeduncular nucleus. Mismatches in the distribution of the tachykinins and tachykinin receptors suggest the possibility of additional tachykinin receptor subtypes. 

Mesencephalon substantia nigra-pars reticulata, interpeduncular nucleus, central gray ventral tegmental area, laterodorsal tegmental nucleus, interpeduncular nucleus... 

Interpeduncular nucleus, central gray, mesencephalic reticular formation Rhombencephalon... 

Grady, S.R., Meinerz, N.M., Cao, J. et al. Nicotinic agonists stimulate acetylcholine release from mouse interpeduncular nucleus a function mediated by a different nAChR than dopamine release from striatum. J. Neurochem. 76 258, 2001. 

Consistent with receptor binding studies, k receptor mRNA is expressed in the claustrum and interpeduncular nucleus as well as the ventral tegmental area. High levels of k receptor mRNA levels are expressed in the substantia nigra pars compacta, suggestive that k receptors may be expressed in dopaminergic neurons with a presynaptic location. 

Figure 18.7 Distribution of iron in human brain. GP, globus pallidus SN, substantia nigra IPN, interpeduncular nucleus TH, thalamus DG, dentate gyrus RN, red nucleus CC, cerebral cortex HIPP, hippocampus CER, cerebellum FC, frontal cortex. (From Crichton and Ward, 2006. Reproduced with permission from John Wiley Sons., Inc.)...

The striatum, the nucleus accumbens, the hippocampus, the lateral nucleus of the hypothalamus, the habenula, the interpeduncular nucleus, the nucleus of the tractus soli-tarius, the raphe nuclei and the medulla oblongata are rich in tachykinin NK1 receptors (Otsuka and Yoshioka, 1993). The predominant expression of N receptors within the spinal dorsal horn is consistent with the assumption that SP and NKA are important messengers here (Bleazard et al., 1994). The distribution of NKi receptors in the peripheral nervous system and in the gut are discussed elsewhere (McLean, 1996 Quartara and Maggi, 1997, 1998). 

In the peripheral (Wessler 1989) as well as central (Wonnacott 1997) nervous system, presynaptic nicotinic autoreceptors were reported to control the release of acetylcholine. In both locations, the consequence of presynaptic nAChR activation most commonly is an increase in both spontaneous and evoked acetylcholine release (MacDermott et al. 1999), whereas presynaptic muscarinic receptors mediate the opposite effect, an autoinhibition. Recent studies have focused on the composition of presynaptic nAChRs (Table 2). In the hippocampus, nicotinic autoreceptors were suggested to be a3/p4 receptors (Tani et al. 1998), but a role of p2 subunits has also been implicated (Lloyd et al. 1998). Likewise, in the neocortex, presynaptic nicotinic autoreceptors are likely to be 04/ p2 receptors (Marchi et al. 2002). In contrast, in the interpeduncular nucleus the autoreceptors were suggested to mainly contain a3 and p4 subunits (Grady et al. 2001). 

GOthert M, Duhrsen U (1979) Effects of 5-hydroxytryptamine and related compounds on the sympathetic nerves of the rabbit heart. Naunyn Schmiedebergs Arch Pharmacol 308 9-18 Gotti C, Zoli M, Clementi F (2006) Brain nicotinic acetylcholine receptors native subtypes and their relevance. Trends Pharmacol Sci 27 482-91 Grady SR, Meinerz NM, Cao J, Reynolds AM, Picciotto MR, Changeux JP, McIntosh JM, Marks MJ, Collins AC (2001) Nicotinic agonists stimulate acetylcholine release from mouse interpeduncular nucleus a function mediated by a different nAChR than dopamine release from striatum. J Neurochem 76 258-68... 

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