Kunkel D D, Schwartzkroin P A
Department of Neurological Surgery, University of Washington, Seattle 98195.
Synapse. 1988;2(4):371-81. doi: 10.1002/syn.890020404.
Immunocytochemical techniques have been used to identify a striking interneuronal population which is immunoreactive for the peptide, somatostatin. The cell population, which is seen most densely in stratum oriens and at the oriens/alveus border of the CA1 region of rabbit hippocampus, was characterized in light and electron microscopic observations. The cells have dendrites which extend parallel to and into the alveus, with occasional processes ascending through stratum pyramidale toward the hippocampal fissure. The dendrites receive numerous synaptic contacts directly onto aspinous dendritic shafts. Axon collaterals ramify profusely within the pyramidale region, and among the proximal apical and basal pyramidal cell dendrites in areas of stratum radiatum and stratum oriens. Somatostatin-like immunoreactive terminals make synaptic contact, primarily of the symmetric type, with the somata and proximal dendrites of pyramidal neurons. Somatostatin-like neurons are found at approximately equal density in the hippocampus of immature (8 days postnatal) and mature (30 days postnatal) rabbit. Double-labelling techniques, to identify both somatostatin-like and glutamic acid decarboxylase (GAD) immunoreactive neurons, demonstrated that a large proportion of the somatostatin neurons were also GABAergic.
免疫细胞化学技术已被用于识别一群引人注目的中间神经元，它们对肽类生长抑素具有免疫反应性。在兔海马CA1区的海马下脚和海马下脚/脑室膜边界中，该细胞群最为密集，通过光镜和电镜观察对其进行了表征。这些细胞具有与脑室膜平行并延伸至脑室膜内的树突，偶尔有突起穿过锥体层向海马裂延伸。树突在无棘的树突干上直接接受大量突触联系。轴突侧支在锥体区域内大量分支，并在辐射层和海马下脚区域的近端顶树突和基底树突之间分支。生长抑素样免疫反应性终末主要与锥体神经元的胞体和近端树突形成对称型突触联系。在未成熟（出生后8天）和成熟（出生后30天）兔的海马中，生长抑素样神经元的密度大致相等。用于识别生长抑素样和谷氨酸脱羧酶（GAD）免疫反应性神经元的双重标记技术表明，大部分生长抑素神经元也是γ-氨基丁酸能的。
