King D G
J Neurocytol. 1976 Apr;5(2):207-37. doi: 10.1007/BF01181657.
The stomatogastric ganglion of the lobster consists of about thiry neurons, mainly large monopolar cells, which have been well characterized physiologically. This paper presents an anatomical description of this ganglion, emphasizing synaptic connections in the neuropil. The neuron cell bodies are located on the dorsal surface of the ganglion. They send processes into the underlying neuropil mass. The neuropil is differentiated into two regions: a core of coarse neuropil consists of large heavily ensheathed processes; a surrounding region of fine-textured synaptic neuropil consists of smaller unsheather processes. Synapses are found only in synaptic neuropil, not in the core of coarse neuropil. Synaptic contacts, about one million in the entire neuropil, are easily recognized by a set of criteria including presynaptic vesicles and pre- and postsynaptic membrane specializations. Most synaptic contacts invole at least three neural processes, usually one pre- and two postsynaptic elements. Synapses are clustered onto irregular swellings or varicosities on neural processes. These varicosities make both pre- and postsynaptic contacts. Three differenty types of presynaptic profile are recognized. Pyloric dilator, ventricular dilator and lateral posterior gastric neurons belong to type A with clear irregular synaptic vesicles. Lateral pyloric, pyloric, anterior median and dorsal gastric neurons belong to type B with larger clear round vesicles. Many unidentified fibres, presumably stomatogastric nerve afferents, blong to type C with both small clear irregular vesicles and also large dense-core vesicles. The synaptic vesicle types are tentatively correlated with neurotransmitter: type A with acetylcholine, type B with an unknown transmitter, possibly glutamate, and type C with dopamine. The distribution of synaptic contacts on the processes of identified neurons reconstructed from serial section is presented in the following paper.
龙虾的口胃神经节由大约30个神经元组成，主要是大型单极细胞，这些细胞在生理上已得到充分表征。本文对该神经节进行了解剖学描述，重点关注神经纤维网中的突触连接。神经元细胞体位于神经节的背表面。它们将突起延伸到下面的神经纤维网团块中。神经纤维网分为两个区域：粗神经纤维网的核心由粗大且被大量包裹的突起组成；质地细密的突触神经纤维网的周围区域由较小的未被包裹的突起组成。突触仅存在于突触神经纤维网中，而不存在于粗神经纤维网的核心中。整个神经纤维网中约有100万个突触接触，通过包括突触前小泡以及突触前和突触后膜特化等一系列标准很容易识别。大多数突触接触涉及至少三个神经突起，通常是一个突触前元件和两个突触后元件。突触聚集在神经突起上不规则的肿胀或膨体上。这些膨体形成突触前和突触后的接触。识别出三种不同类型的突触前轮廓。幽门扩张肌、心室扩张肌和胃后外侧神经元属于A 型，具有清晰的不规则突触小泡。幽门外侧、幽门、前正中及胃背侧神经元属于B型，具有较大的清晰圆形小泡。许多未识别的纤维，可能是口胃神经传入纤维，属于C型，既有小的清晰不规则小泡，也有大的致密核心小泡。突触小泡类型初步与神经递质相关：A型与乙酰胆碱相关，B型与一种未知递质（可能是谷氨酸）相关，C型与多巴胺相关。后续论文将呈现从连续切片重建的已识别神经元突起上突触接触的分布情况。
