Modulatory Actions

Clemens S., Hochman S. (2004). Conversion of the modulatory actions of dopamine on spinal reflexes from depression to facilitation in D3 receptor knock-out mice. J. Neurosci 24, 11337-45. 

Histamine also induces antinociceptive (i.e. pain-relieving) responses in animals after microinjection into several brain regions [73, 74]. H, and H2 mechanisms are significant and both neuronal and humoral mechanisms may be involved. Brain H2 receptors appear to mediate some forms of endogenous analgesic responses, especially those elicited by exposure to stressors [75]. Many of the modulatory actions of histamine discussed above appear to be activated as part of stress responses. For reasons that remain unclear, histamine releasers, such as thioperamide, show only mild, biphasic antinociceptive actions, even though histamine is a potent and effective analgesic substance. Outside the brain, both H and H3 receptors exist on certain types of sensory nerves and activation of these receptors promotes and inhibits, respectively, peripheral nerve transmission related to pain and/or inflammation [76,77]. 

Emptage NJ, Marcus EA, Stark LL, et al Differential modulatory actions of serotonin in aphysia sensory neurons imphcations for development and learning. Semin Neurosci 6 21-33, 1994... 

Lee M, Strahlendorf JC, Strahlendorf HK Modulatory action of serotonin on glutamate induced excitation of cerebellar Purkinje cells. Brain Res 361 107-113, 1986... 

Jhamandas, K.H., Sutak, M., Flenderson, G. Antinociceptive and morphine modulatory actions of spinal orphanin FQ, Can. J. Physiol. Pharmacol. 1998, 76, 314-324. 

Bonsi R, Cuomo D., De Persis C., Centonze D., Bemardi G., Calabresi P., and Pisani A. (2005). Modulatory action of metabotropic glutamate receptor (mGluR) 5 on mGluRl function in striatal cholinergic interneurons. Neuiopharmacology 49(Suppl 1) 104—113. 

Cannabinoids might alleviate some parkinsonian symptoms by their remarkable receptor-mediated modulatory action in the basal ganglia output nuclei. Moreover, it was recently observed that some cannabinoids are potent antioxidants that can protect neurons from death even without cannabinoid receptor activation. It seems that cannabinoids could delay or even stop progressive degeneration of brain dopaminergic systems, a process for which there is presently no prevention. 

Levine MS, Altemus KL, Cepeda C, Cromwell HC, Crawford C, Ariano MA, Drago J, Sibley DR, Westphal H (1996) Modulatory actions of dopamine on NMDA receptor-mediated responses are reduced in D1 A-deficient mutant mice. J Neurosci 75 5870-5882. 

It should be acknowledged that understanding of the effects of dopamine on whole cell behavior, in terms of modulatory effects on ion channels, is at a more preliminary and somewhat speculative stage. Data on the modulation of individual channels by dopamine now has to be put in the perspective of the membrane potential fluctuations of the whole cell. A detailed and quantitative analysis is crucial to understanding the modulatory actions of dopamine on membrane currents, because exactly which currents are available depends on the recent history of the cell, for this is what determines which of the many currents are turned on and thus available for modulation by dopamine. 

Dopamine Dl receptor activation enhances NMDA-mediated excitatory responses (Cepeda et al., 1993 Cepeda and Levine, 1998). The modulatory actions of dopamine on NMD A receptor mediated responses are reduced in Dl deficient mice (Levine et al., 1996a), supporting a specific role for Dl receptors in enhancement. However, this enhancement involves a complex interplay of actions both on the NMDA receptors and also on the voltage-sensitive calcium channels (VSCC). In particular, the activation of VSCC conductances on the distal dendrites contributes to the enhancement of NMDA currents by dopamine. This mechanism of enhancement involves increased regenerative amplification of synaptic responses by increased VSCC currents (Cepeda et al., 1993, 1998 Cepeda and Levine, 1998). Synaptic responses may also be increased directly by... 

Song L-N, Huse B, Rusconi S, Simons SS Jr. Transactivation specificity of glucocorticoi vs. progesterone receptors Role of 106. functionally different interactions of transcription factors with amino- and carboxyl-terminal receptor domains. J. Biol. Chem. 2001 276 24806-24816 Szapary D, Song L-N, He Y, Simons 107. SS, Jr. Comparison of modulatory actions of GME, GMEB-2,... 

The influence of neuronal nitric oxide synthase (nNOS) on renal arteriolar tone has been studied in the perfused juxtamedullary nephron preparation [126]. Superfusion with a specific nNOS inhibitor decreased afferent and efferent arteriolar diameters, and these decreases in arteriolar diameters were prevented by interruption of distal volume dehvery by papillectomy. When volume delivery to the macula densa segment was increased, afferent arteriolar vasoconstrictor responses to the nNOS inhibitor were enhanced, but this effect was again completely prevented after papillectomy. In contrast, the arteriolar diameter responses to a nonselective NOS inhibitor were only attenuated by papillectomy. Specific nNOS inhibition enhanced the efferent arteriolar vasoconstrictor response to ANG II but did not alter the afferent arteriolar vasoconstrictor responsiveness to ANG II. In contrast, non specific NOS inhibition enhanced both afferent and efferent arteriolar vasoconstrictor responses to ANG It. This study demonstrates that the modulating influence of nNOS on afferent arteriolar tone of juxtamedullary nephrons is dependent on distal tubular fluid flow and that nNOS exerts a differential modulatory action on... 

Herz A. Role of immune processes in peripheral opiate analgesia. Adv Exp Med Biol 1995 373 193-199. Hori T, Oka T, Hosoi M, Aou S. Pain modulatory actions of cytokines and prostaglandin E2 in the brain. Ann... 

Schnabel, C.A., Abate-Shen, C. 1996. Repression by HoxA7 is mediated by the homeodomain and the modulatory action of its N-terminal-arm residues. Mol. Cell. Biol. 16, 2678-2688. 

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