TY - JOUR
T1 - Induction of Fos-like immunoreactivity in the basal ganglia by ether anaesthesia
T2 - Effects of injections of muscimol in rostral versus caudal substantia nigra pars reticulata
AU - Shehab, S.
AU - Julyan, T.
N1 - Funding Information:
Acknowledgements We are grateful to Dr. G. Evan for his kind gift of c-fos antibodies, to Professor L.J. Garey and Dr. P. Redgrave for their invaluable comments on the manuscript and Dr. A. Todd for his assistance with the confocal microscopy. This work was partly supported by a grant from the Faculty of Medicine and Health Sciences of the UAE University.
PY - 2002
Y1 - 2002
N2 - Exposing rats to ether anaesthesia for 20 min induced a massive expression of c-fos like (FL) immunoreactivity in specific regions of the brain, including the basal ganglia. This expression of FL immunoreactivity in the basal ganglia was successfully blocked by local injections of muscimol (GABAA agonist) in the substantia nigra (SN). This model was used to investigate our recent finding that inhibition of caudal SN pars reticulata (SNpr) with muscimol is more potent in suppressing the motor component of tonic seizures than comparable inhibition of the rostral part. Two experiments were carried out. In experiment I, the effects of ether anaesthesia on c-fos expression in the brain were investigated. Brain sections taken from untreated control rats and stained immunocytochemically with c-fos antibodies. The results showed no FL immunoreactivity in the SNpr, subthalamic nucleus (STN), entopeduncular nucleus (EPN) and globus pallidus (GP). However, a few scattered FL immunoreactive nuclei were observed in the caudate-putamen (CPu). In rats exposed to ether, numerous FL immunoreactive nuclei were detected in the SNpr, STN, EPN and GP. In the CPu, a slight increase in number of labelled nuclei was noted. In experiment II, rats were prepared with intracranial chronic cannulae through which the effects of muscimol (60 ng) injected unilaterally in either the rostral or caudal SNpr on c-fos expression induced by ether were investigated. Injections in both sites caused remarkable suppression of the ether-induced c-fos throughout the ipsilateral SNpr; however, the rostral injection also inhibited the expression of c-fosin the STN, EPN and GP. The implications of these results for microinjection mapping studies of the SN are discussed.
AB - Exposing rats to ether anaesthesia for 20 min induced a massive expression of c-fos like (FL) immunoreactivity in specific regions of the brain, including the basal ganglia. This expression of FL immunoreactivity in the basal ganglia was successfully blocked by local injections of muscimol (GABAA agonist) in the substantia nigra (SN). This model was used to investigate our recent finding that inhibition of caudal SN pars reticulata (SNpr) with muscimol is more potent in suppressing the motor component of tonic seizures than comparable inhibition of the rostral part. Two experiments were carried out. In experiment I, the effects of ether anaesthesia on c-fos expression in the brain were investigated. Brain sections taken from untreated control rats and stained immunocytochemically with c-fos antibodies. The results showed no FL immunoreactivity in the SNpr, subthalamic nucleus (STN), entopeduncular nucleus (EPN) and globus pallidus (GP). However, a few scattered FL immunoreactive nuclei were observed in the caudate-putamen (CPu). In rats exposed to ether, numerous FL immunoreactive nuclei were detected in the SNpr, STN, EPN and GP. In the CPu, a slight increase in number of labelled nuclei was noted. In experiment II, rats were prepared with intracranial chronic cannulae through which the effects of muscimol (60 ng) injected unilaterally in either the rostral or caudal SNpr on c-fos expression induced by ether were investigated. Injections in both sites caused remarkable suppression of the ether-induced c-fos throughout the ipsilateral SNpr; however, the rostral injection also inhibited the expression of c-fosin the STN, EPN and GP. The implications of these results for microinjection mapping studies of the SN are discussed.
KW - Basal ganglia
KW - Ether
KW - Muscimol
KW - Substantia nigra
KW - c-fos
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U2 - 10.1007/s00221-001-0907-6
DO - 10.1007/s00221-001-0907-6
M3 - Article
C2 - 11807577
AN - SCOPUS:0036139640
SN - 0014-4819
VL - 142
SP - 227
EP - 240
JO - Experimental Brain Research
JF - Experimental Brain Research
IS - 2
ER -