Untitled

Abstract

Long-term potentiation of CA1 field potentials was induced by weak tetanic orthodromic stimulation of the Schaffer collateral/commissural fibers in isolated hippocampal slices perfused with a medium containing arginine vasopressin fragment AVP(4-9)in micromolar concentrations. It is hypothesized that AVP(4-9)affects induction of long-term potentiation at the intracellular level.

Vasopressin facilitates GABAergic transmission in rat hippocampus via activation of V1A receptors

“…In line with our results, previous work has also shown that AVP excites hippocampal pyramidal neurons (Mizuno et al, 1984; Muhlethaler et al, 1982; Tiberiis et al, 1983a). Furthermore, AVP has been shown to increase LTP in CA1 region (Chepkova et al, 1995; Chepkova et al, 2001; Rong et al, 1993) and the dentate gyrus (Chen et al, 1993; Dubrovsky et al, 2003). AVP-mediated direct excitation of CA1 pyramidal neurons and indirect augmentation of glutamatergic transmission onto CA1 pyramidal neurons likely contribute to AVP-induced enhancement of learning and memory (Alescio-Lautier et al, 2000; Alescio-Lautier and Soumireu-Mourat, 1998).…”

“…In addition, the hippocampus also expresses high-density of vasopressin receptors (Audigier and Barberis, 1985; Brinton et al, 1984; Costantini and Pearlmutter, 1984; De Kloet et al, 1985). Consistent with the distribution of vasopressin and vasopressin receptors in the hippocampus, application of vasopressin enhances synaptic transmission and induces long-term potentiation (LTP) in CA1 region (Chepkova et al, 1995; Chepkova et al, 2001; Rong et al, 1993) and the dentate gyrus (Chen et al, 1993; Dubrovsky et al, 2003). Whereas vasopressin has been shown to excite hippocampal pyramidal neurons (Mizuno et al, 1984; Muhlethaler et al, 1982; Tiberiis et al, 1983a), recordings of the field potentials demonstrate that the pyramidal discharge is inhibited by vasopressin (Albeck and Smock, 1988) suggesting that vasopressin also excites non-pyramidal inhibitory interneurons to exert indirect inhibitory effects on pyramidal neurons (Muhlethaler et al, 1984).…”

Designing nootropic dipeptides using an evolutionary-genetic approach

“…165°C. Total yield, 0.74 g (64.3%); R f , 0.47 (dioxane -water, 10 : 1), 0.53 (butanol -acetic acid -water, 4 : 1 : 1); 0.57 (isopropanol -ammonia, 7 His-OMe · 2HCl). This salt was obtained using the conventional method [14] with a yield of 85.8%; m.p.…”

“…The most active representative of this group was pyroglutamylasparagine amide [4], which is identical with arginine vasopressin AVP (4)(5)(6)(7)(8)(9), the N-terminal fragment of the main metabolite of vasopressin. This endogenous hexapeptide is now considered one of the main regulators involved in learning and memory [5 -7].…”

“…This endogenous hexapeptide is now considered one of the main regulators involved in learning and memory [5 -7]. The AVP(4-9) fragment enters into the vasopressin family of peptides, which also contains AVP (4)(5)(6)(7)(8), AVP (5)(6)(7)(8)(9), and AVP (5)(6)(7)(8) [8,9]. All these peptides possess a high mnemonic activity, while being deprived of the hormonal properties of vasopressin.…”