Mueller A L, Kunkel D D, Schwartzkroin P A
Cell Mol Neurobiol. 1986 Dec;6(4):363-79. doi: 10.1007/BF00711406.
The electrophysiological actions of somatostatin (somatotropin release inhibiting factor; SRIF) were investigated in the in vitro hippocampal slice preparation. Intracellular recordings were obtained from pyramidal neurons in area CA1 in slices of hippocampus from guinea pigs and rabbits. Somatostatin, applied via micropressure ejection to CA1 pyramidal-cell somata, was primarily excitatory. The effects, however, were quite variable, with nearly all cells displaying pronounced tachyphylaxis. A majority of cells was depolarized by SRIF, but hyperpolarizations or biphasic depolarization/hyperpolarization responses were also recorded. Only minimal conductance changes were associated with the SRIF-induced voltage changes. Depletion of SRIF, by injection of the intact animal with cysteamine several hours before preparing slices, resulted in no obvious abnormalities in hippocampal slice electrophysiology. Our results obtained with application of exogenous SRIF are consistent with the concept that SRIF acts as an excitatory neurotransmitter/neuromodulator in hippocampus. However, our attempts to demonstrate endogenous SRIF action have thus far been unsuccessful.
在体外海马脑片制备中研究了生长抑素（促生长激素释放抑制因子；SRIF）的电生理作用。从豚鼠和兔子海马脑片CA1区的锥体神经元进行细胞内记录。通过微压喷射将生长抑素施加到CA1锥体细胞的胞体上，其主要作用是兴奋性的。然而，这些效应变化很大，几乎所有细胞都表现出明显的快速耐受性。大多数细胞被SRIF去极化，但也记录到了超极化或双相去极化/超极化反应。与SRIF诱导的电压变化相关的电导变化很小。在制备脑片前数小时给完整动物注射半胱胺以耗尽SRIF，并未导致海马脑片电生理出现明显异常。我们应用外源性SRIF获得的结果与SRIF在海马中作为兴奋性神经递质/神经调节剂起作用的概念一致。然而，我们迄今证明内源性SRIF作用的尝试尚未成功。
