Glickfeld Lindsey L, Scanziani Massimo
Neuroscience Graduate Program and Neurobiology Section, Division of Biology, University of California San Diego, La Jolla, California 92093, USA.
Nat Neurosci. 2006 Jun;9(6):807-15. doi: 10.1038/nn1688. Epub 2006 Apr 30.
Cannabinoids are powerful modulators of inhibition, yet the precise spike timing of cannabinoid receptor (CB1R)-expressing inhibitory neurons in relation to other neurons in the circuit is poorly understood. Here we found that the spike timing of CB1R-expressing basket cells, a major target for cannabinoids in the rat hippocampus, was distinct from the other main group of basket cells, the CB1R-negative. Despite receiving the same afferent inputs, the synaptic and biophysical properties of the two cell types were tuned to detect different features of activity. CB1R-negative basket cells responded reliably and immediately to subtle and repetitive excitation. In contrast, CB1R-positive basket cells responded later and did not follow repetitive activity, but were better suited to integrate the consecutive excitation of independent afferents. This temporal separation in the activity of the two basket cell types generated distinct epochs of somatic inhibition that were differentially affected by endocannabinoids.
大麻素是强大的抑制调节因子,但表达大麻素受体(CB1R)的抑制性神经元相对于回路中其他神经元的精确放电时间却知之甚少。在这里,我们发现,在大鼠海马体中,表达CB1R的篮状细胞(大麻素的主要作用靶点)的放电时间与另一主要篮状细胞群(CB1R阴性)不同。尽管两种细胞类型接受相同的传入输入,但它们的突触和生物物理特性经过调整,以检测不同的活动特征。CB1R阴性篮状细胞对细微且重复的兴奋可靠且立即做出反应。相比之下,CB1R阳性篮状细胞反应较晚,不跟随重复活动,但更适合整合独立传入神经的连续兴奋。这两种篮状细胞类型活动的时间分离产生了不同的体细胞抑制时期,这些时期受到内源性大麻素的不同影响。