椎实螺（Lymnaea stagnalis L.）嗅检神经元对化学刺激和神经递质的不同反应

Distinct responses of osphradial neurons to chemical stimuli and neurotransmitters in Lymnaea stagnalis L.

作者信息

Kamardin N, Szücs A, Rózsa K S

机构信息

Balaton Limnological Research Institute, Hungarian Academy of Sciences, Tihany, Hungary.

出版信息

Cell Mol Neurobiol. 1999 Apr;19(2):235-47. doi: 10.1023/a:1006929211493.

DOI:10.1023/a:1006929211493

PMID:10081607

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11545630/

Abstract

In Lymnaea stagnalis L. (Pulmonata, Basommatophora) the neurons in the osphradium were visualized by staining through the inner right parietal nerve by 5,6-carboxyfluorescein (5,6-CF). Three types of neurons were identified: three large ganglionic cells (GC1-3; 80-100 microns), the small putative sensory neurons (SC; 20 microns) and very small sensory cells (3-5 microns). 2. The ganglionic and putative sensory neurons were investigated by whole cell patch-clamp method in current-clamp condition. The three giant ganglionic neurons (GC1-3) located closely to the root of osphradial nerve, had a membrane potential (MP) between -30 and -70 mV and showed tonic or bursting activities. The small putative sensory cells (SCs) scattered throughout the osphradial ganglion, possessed a MP between -25 and -55 mV and showed an irregular firing pattern with membrane oscillations. At resting MP the GC1-3 cells were depolarized and increased the frequency of their firing, while the SCs were hyperpolarized and inhibited by NaCl (10(-2) M) and L-aspartate (10(-5) M) applied to the osphradium. 3. 5-Hydroxytryptamine (5HT, 10(-6) M), gamma-aminobutyric acid (GABA; 10(-6) M) and the GABAB agonist baclofen (10(-6) M) depolarized the neurons GC1-3 and increased their firing frequency. In contrast, on the GC1-3 neurons, acetylcholine (Ach; 10(-6) M) and FMRFamide (10(-6) M) caused hyperpolarization and cessation of the firing activity. The 5HT effect was blocked by mianserin (10(-6) M) but picrotoxin (10(-5) M) failed to block the GABA-induced effect on the GC1-3 cells. 4. The small putative sensory neurons (SCs) were excited by Ach (10(-6) M) and 5HT (10(-6) M) but were inhibited by GABA (10(-6) M). FMRFamide (10(-6) M) had a biphasic response. The Ach effect was blocked by hexamethonium (10(-6) M) and tetraethylammonium (10(-6) M), indicating the involvement of nicotinic cholinergic receptors. 5. The distinct responses of the two populations of osphradial neurons to chemical stimuli and neurotransmitters suggest that they can differently perceive signals from environment and hemolymph.

摘要

在椎实螺（肺螺亚纲，基眼目）中，通过用5,6 - 羧基荧光素（5,6 - CF）经右内侧顶神经染色，视嗅球中的神经元得以可视化。鉴定出了三种类型的神经元：三个大型神经节细胞（GC1 - 3；80 - 100微米）、小型假定感觉神经元（SC；20微米）和非常小的感觉细胞（3 - 5微米）。2. 在电流钳制条件下，采用全细胞膜片钳方法对神经节和假定感觉神经元进行了研究。位于视嗅球神经根部附近的三个大型神经节神经元（GC1 - 3），其膜电位（MP）在 - 30至 - 70毫伏之间，表现出紧张性或爆发性活动。散布在视嗅球神经节中的小型假定感觉细胞（SCs），其MP在 - 25至 - 55毫伏之间，表现出带有膜振荡的不规则放电模式。在静息膜电位时，GC1 - 3细胞去极化并增加其放电频率，而SCs则超极化并受到施加于视嗅球的氯化钠（10⁻² M）和L - 天冬氨酸（10⁻⁵ M）的抑制。3. 5 - 羟色胺（5HT，10⁻⁶ M）、γ - 氨基丁酸（GABA；10⁻⁶ M）和GABAB激动剂巴氯芬（10⁻⁶ M）使GC1 - 3神经元去极化并增加其放电频率。相反，对于GC1 - 3神经元，乙酰胆碱（Ach；10⁻⁶ M）和FMRF酰胺（10⁻⁶ M）引起超极化并使放电活动停止。5HT的作用被米安色林（10⁻⁶ M）阻断，但苦味毒（10⁻⁵ M）未能阻断GABA对GC1 - 3细胞的诱导作用。4. 小型假定感觉神经元（SCs）被Ach（10⁻⁶ M）和5HT（10⁻⁶ M）兴奋，但被GABA（10⁻⁶ M）抑制。FMRF酰胺（10⁻⁶ M）有双相反应。Ach的作用被六甲铵（10⁻⁶ M）和四乙铵（10⁻⁶ M）阻断，表明烟碱型胆碱能受体参与其中。5. 视嗅球神经元的这两个群体对化学刺激和神经递质的不同反应表明，它们能够以不同方式感知来自环境和血淋巴的信号。