Role of the substantia nigra in antiaggressive and anticonvulsant effects of diazepam during pharmacological kindling

1991 ◽  
Vol 22 (4) ◽  
pp. 356-359
Author(s):  
A. A. Shandra ◽  
L. S. Godlevskii ◽  
A. M. Mazarati ◽  
R. F. Makul'kin
1997 ◽  
Vol 77 (3) ◽  
pp. 1635-1638 ◽  
Author(s):  
M. Clara Sañudo-Peña ◽  
J. Michael Walker

Sañudo-Peña, M. Clara and J. Michael Walker. Role of the subthalamic nucleus in cannabinoid actions in the substantia nigra of the rat. J. Neurophysiol. 77: 1635–1638, 1997. The effect of cannabinoids on the excitatory input to the substantia nigra reticulata (SNr) from the subthalamic nucleus was explored. For this purpose a knife cut was performed rostral to the subthalamic nucleus to isolate the subthalamic nucleus and the SNr from the striatum, a major source of cannabinoid receptors to the SNr. The data showed that the cannabinoid agonist WIN55,212-2 blocked the increase in the firing rate of SNr neurons induced by stimulation of the subthalamic nucleus with bicuculline. Furthermore, the cannabinoid antagonist SR141716A antagonized the effect of the cannabinoid agonist. This study showed that cannabinoids regulate not only the striatonigral pathway, as previously reported, but also the subthalamonigral pathway. The opposite influences of these two inputs to the SNr, inhibitory and excitatory respectively, suggest that endogenous cannabinoids play a major role in the physiological regulation of the SNr.


2004 ◽  
Vol 101 (26) ◽  
pp. 9843-9848 ◽  
Author(s):  
L. Zecca ◽  
A. Stroppolo ◽  
A. Gatti ◽  
D. Tampellini ◽  
M. Toscani ◽  
...  

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Daniel J Galtieri ◽  
Chad M Estep ◽  
David L Wokosin ◽  
Stephen Traynelis ◽  
D James Surmeier

Burst spiking in substantia nigra pars compacta (SNc) dopaminergic neurons is a key signaling event in the circuitry controlling goal-directed behavior. It is widely believed that this spiking mode depends upon an interaction between synaptic activation of N-methyl-D-aspartate receptors (NMDARs) and intrinsic oscillatory mechanisms. However, the role of specific neural networks in burst generation has not been defined. To begin filling this gap, SNc glutamatergic synapses arising from pedunculopotine nucleus (PPN) neurons were characterized using optical and electrophysiological approaches. These synapses were localized exclusively on the soma and proximal dendrites, placing them in a good location to influence spike generation. Indeed, optogenetic stimulation of PPN axons reliably evoked spiking in SNc dopaminergic neurons. Moreover, burst stimulation of PPN axons was faithfully followed, even in the presence of NMDAR antagonists. Thus, PPN-evoked burst spiking of SNc dopaminergic neurons in vivo may not only be extrinsically triggered, but extrinsically patterned as well.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Arman Rahimmi ◽  
Ilaria Peluso ◽  
Aref Rajabi ◽  
Kambiz Hassanzadeh

There are still unknown mechanisms involved in the development of Parkinson’s disease (PD), which elucidating them can assist in developing efficient therapies. Recently, studies showed that genes located on the human chromosomal location 22q11.2 might be involved in the development of PD. Therefore, the present study was designed to evaluate the role of two genes located on the chromosomal location (miR-185 and SEPT5), which were the most probable candidates based on our bibliography. In vivo and in vitro models of PD were developed using male Wistar rats and SHSY-5Y cell line, respectively. The expression levels of miR-185, SEPT5, LRRK2, and PARK2 genes were measured at a mRNA level in dopaminergic areas of rats’ brains and SHSY-5Y cells using the SYBR Green Real-Time PCR Method. Additionally, the effect of inhibition on the genes or their products on cell viability and gene expression pattern in SHSY-5Y cells was investigated. The level of miR-185 gene expression was significantly decreased in the substantia nigra (SN) and striatum (ST) of the rotenone-treated group (control group) compared to the healthy normal group (P<0.05). In addition, there was a significant difference in the expression of SEPT5 gene (P<0.05) in the substantia nigra between two studied groups. The results of an in vitro study showed no significant change in the expression of the genes; however, the inhibition on miR-185 gene expression led to the increase in LRRK2 gene expression in SHSY-5Y cells. The inhibition on LRRK2 protein also decreased the cellular toxicity effect of rotenone on SHSY-5Y cells. The results suggested the protective role of miR-185 gene in preventing the development of PD.


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