Receptors depression

Kainate receptors mediate a depression of evoked excitatory synaptic transmission in areas CA1 (40,88-90) and CA3 (35,37,91,92) of the hippocampus. There is strong evidence that in area CA1 the locus of this effect is presynaptic. Thus, activation of kainate receptors depresses release of L-glutamate from synaptosomes (88) and depresses both NMDA and AMPA receptor-mediated components of the evoked EPSC in parallel (88,90). Furthermore, the effects of kainate receptor activation on excitatory synaptic transmission in CA1 are associated with changes in presynaptic Ca2+ (89), an increase in paired-pulse facilitation (35,88,89), and a reduction in quantal content, as assessed using 1/CV2, but no change in mEPSC amplitude (90). 

Frerking, M., Schmitz, D., Zhou, Q., Johansen, J., and Nicoll, R. A. (2001) Kainate receptors depress excitatory synaptic transmission at CA3-CA1 synapses in the hippocampus via a direct presynaptic action. J. Neurosci. 21, 2958-2966. 

Deakin JF. (1988). 5HT2 receptors, depression and anxiety. Pharmacol Biochem Behav. 29(4) 819-... 

Mechanism of Action An anticholinergic that reduces excitability of labyrinthine receptors, depressing conduction in the vestibular cerebellar pathway. Therapeutic Effect Prevents motion-induced nausea and vomiting. 

Doreulee N, Yanovsky Y, Flagmeyer I, Stevens DR, Haas HL, Brown RE (2001) Histamine H3 receptors depress synaptic transmission in the corticostriatal pathway. Neuropharmacology 40 106-13... 

Armstrong JN, Brust TB, Lewis RG, Mac Vicar BA (2002) Activation of presynaptic P2X7-like receptors depresses mossy fiber-CA3 synaptic transmission through p38 mitogen-activated pro-teink. J Neurosci 22 5938 15... 

Fig. 6. Activation of two distinct types of metabotropic glutamate receptor depresses monosynaptic reticulospinal EPSPs. Effect of (S)-2-amino-2-methyl-4-phosphonobutanoic acid (MAP4) on (1 S,3/f)-1 -aminocyclopentane-1,3-dicarboxylic acid/( 1 S,3i )-ACPD/- and L(-l-)-2-amino-4-phosphonobutyric...

Krieger P, El Manira A, Grillner S (1996) Activation of pharmacologically distinct metabotropic glutamate receptors depresses reticulospinal-evoked monosynaptic EPSPs in the lamprey spinal cord. J Neurophysiol 76 3834-3841. 

Neurokinin signaling Tachykinin receptors Depression, Urogenital... 

Forsythe, I.D. and Clements, J.D. (1990). Presynaptic glutamate receptors depress excitatory monosynaptic transmission between mouse hippocampal neurones. J. Physiol. (London) 429 1-16. 

Depressed persons who commit suicide have been found to have low levels of 5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in their brain stem (Mann et al., 1990). Low levels of 5-HIAA also have been found in the cerebrospinal fluid of suicide victims. This has been attributed to a decreased release of 5-HT, rather than to lower numbers 5-HT receptors. Depressed persons also have low brain levels of norepinephrine, as well as 5-HT. 

Melatonin [73-31-4] C 2H N202 (31) has marked effects on circadian rhythm (11). Novel ligands for melatonin receptors such as (32) (12), C2yH2gN202, have affinities in the range of 10 Af, and have potential use as therapeutic agents in the treatment of the sleep disorders associated with jet lag. Such agents may also be usehil in the treatment of seasonal affective disorder (SAD), the depression associated with the winter months. Histamine (see Histamine and histamine antagonists), adenosine (see Nucleic acids), and neuropeptides such as corticotropin-like intermediate lobe peptide (CLIP) and vasoactive intestinal polypeptide (VIP) have also been reported to have sedative—hypnotic activities (7). 

Midazolam and diazepam decrease arterial pressure without a change ia heart rate. Like thiopeatoae, midazolam is a respiratory depressant. Advantages of midazolam are its amnestic effect, coupled with less postoperative depression (102). A reversal agent for the benzodiazepiaes has also become available. Flumazenil [78755-81-4] C25H24FN2O2, (5) displaces the beazodiazepiaes from their receptor but has Httie demoastrable activity of its owa (103,104). 

Future Outlook for Antidepressants. Third-generation antidepressants are expected to combine superior efficacy and improved safety, but are unlikely to reduce the onset of therapeutic action in depressed patients (179). Many dmgs in clinical development as antidepressive agents focus on estabhshed properties such as inhibition of serotonin, dopamine, and/or noradrenaline reuptake, agonistic or antagonistic action at various serotonin receptor subtypes, presynaptic tt2-adrenoceptor antagonism, or specific monoamine—oxidase type A inhibition. Examples include buspirone (3) (only... 

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