Hippocampus nicotinic acetylcholine receptors

Dani, J.A., Radcliffe, K.A., Pidoplichko, V.I. Variations in desensitization of nicotinic acetylcholine receptors from hippocampus and midbrain dopamine areas. Eur. J. Pharmacol. 393 31, 2000. 

Elgoyhen AB, Vetter DE, Katz E, RotWinCV, Heinemann SF, Boulter J (2001) alO a determinant of nicotinic cholinergic receptor function in mammalian vestibular and chochlear mechanosen-sory hair cells. Proc Natl Acad Sci 98 3501-3506 Fabian-Fine R, Skehel P, Erington ML, Davies HA, Sher E, Stewart MG, Fine A (2001) Ultra-structural distribution of the a7 nicotinic acetylcholine receptor subunit in rat hippocampus. J Neurosci 21 7993-8003... 

Alkondon M, Albuquerque EX (2001) Nicotinic acetylcholine receptor alpha 7 and alpha 4beta 2 subtypes differentially control GABAergic input to CA1 neurons in rat hippocampus. J Neurophysiol 86 3043-55... 

Liu Y, Ford B, Mann MA, Fischbach GD. 2001. Neuregulins increase alpha7 nicotinic acetylcholine receptors and enhance excitatory synaptic transmission in GABAergic interneurons of the hippocampus. J Neurosci 21 5660-5669. 

The arborvitae seed improves cognitive function and a7-nicotinic acetylcholine receptor (a7nAChR) protein expression in the hippocampus on AD model rats [195]. 

There are many similarities in the occurrence of biosilicification in both systems. One of the major neurochemical features of Alzheimer s disease is the marked reduction of nicotinic acetylcholine receptor in relevant diseased brain regions such as the cerebral cortex and hippocampus (Oddo LaFerle, 2006). An important use of chalcedony crystals from electric organs is, maybe, in relation with the human medicine. 

Aracava, Y, Deshpande, S.S., Swanson, K.L., et al., 1987. Nicotinic acetylcholine receptors in cultured neurons from the hippocampus and brain stem of the rat characterized by single channel recording. FEES Lett. 222 (1), 63-70. Aronstam, R.S., Witkop, B., 1981. Anatoxin-a interactions with cholinergic synaptic molecules. Proc. Nat. Acad. Sci. USA 78 (7 I), 4639-4643. 

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). 

Actions of acetylcholine (ACh) are referred to as muscarinic based on the observation that muscarine acts selectively at certain sites and, quahtatively, produces the same effects as ACh. Peripheral muscarinic acetylcholine receptors are found primarily on autonomic effector cells innervated by postganghonic parasympathetic nerves and on some cells that receive little or no cholinergic innervation but express muscarinic receptors e.g., vascular endothelial cells). There are also muscarinic receptors in ganglia and the adrenal meduUa, where muscarinic stimulation seems to modulate the effects of nicotinic stimulation. Within the central nervous system (CNS), the hippocampus, cortex, and thalamus have high densities of muscarinic receptors. 

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