Intracellular analysis of synaptic potentials in rat neostriatum following stimulation of the cerebral cortex, thalamus, and substantia nigra

1980 ◽  
Vol 5 (6) ◽  
pp. 725-733 ◽  
Author(s):  
C.P. Vandermaelen ◽  
S.T. Kitai
1999 ◽  
Vol 82 (2) ◽  
pp. 925-933 ◽  
Author(s):  
Yuji Iribe ◽  
Kevin Moore ◽  
Kevin C. H. Pang ◽  
James M. Tepper

The subthalamic nucleus (STN) is one of the principal sources of excitatory glutamatergic input to dopaminergic neurons of the substantia nigra, yet stimulation of the STN produces both excitatory and inhibitory effects on nigral dopaminergic neurons recorded extracellularly in vivo. The present experiments were designed to determine the sources of the excitatory and inhibitory effects. Synaptic potentials were recorded intracellularly from substantia nigra pars compacta dopaminergic neurons in parasagittal slices in response to stimulation of the STN. Synaptic potentials were analyzed for onset latency, amplitude, duration, and reversal potential in the presence and absence of GABA and glutamate receptor antagonists. STN-evoked depolarizing synaptic responses in dopaminergic neurons reversed at approximately −31 mV, intermediate between the expected reversal potential for an excitatory and an inhibitory postsynaptic potential (EPSP and IPSP). Blockade of GABAA receptors with bicuculline caused a positive shift in the reversal potential to near 0 mV, suggesting that STN stimulation evoked a near simultaneous EPSP and IPSP. Both synaptic responses were blocked by application of the glutamate receptor antagonist, 6-cyano-7-nitroquinoxalene-2,3-dione. The confounding influence of inhibitory fibers of passage from globus pallidus and/or striatum by STN stimulation was eliminated by unilaterally transecting striatonigral and pallidonigral fibers 3 days before recording. The reversal potential of STN-evoked synaptic responses in dopaminergic neurons in slices from transected animals was approximately −30 mV. Bath application of bicuculline shifted the reversal potential to ∼5 mV as it did in intact animals, suggesting that the source of the IPSP was within substantia nigra. These data indicate that electrical stimulation of the STN elicits a mixed EPSP-IPSP in nigral dopaminergic neurons due to the coactivation of an excitatory monosynaptic and an inhibitory polysynaptic connection between the STN and the dopaminergic neurons of substantia nigra pars compacta. The EPSP arises from a direct monosynaptic excitatory glutamatergic input from the STN. The IPSP arises polysynaptically, most likely through STN-evoked excitation of GABAergic neurons in substantia nigra pars reticulata, which produces feed-forward GABAA-mediated inhibition of dopaminergic neurons through inhibitory intranigral axon collaterals.


1979 ◽  
Vol 173 (3) ◽  
pp. 471-487 ◽  
Author(s):  
R. Morris ◽  
M.S. Levine ◽  
E. Cherubini ◽  
N.A. Buchwald ◽  
C.D. Hull

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Igor Lavrov ◽  
Timur Latypov ◽  
Elvira Mukhametova ◽  
Brian Lundstrom ◽  
Paola Sandroni ◽  
...  

AbstractElectrical stimulation of the cerebral cortex (ESCC) has been used to treat intractable neuropathic pain for nearly two decades, however, no standardized approach for this technique has been developed. In order to optimize targeting and validate the effect of ESCC before placing the permanent grid, we introduced initial assessment with trial stimulation, using a temporary grid of subdural electrodes. In this retrospective study we evaluate the role of electrode location on cerebral cortex in control of neuropathic pain and the role of trial stimulation in target-optimization for ESCC. Location of the temporary grid electrodes and location of permanent electrodes were evaluated in correlation with the long-term efficacy of ESCC. The results of this study demonstrate that the long-term effect of subdural pre-motor cortex stimulation is at least the same or higher compare to effect of subdural motor or combined pre-motor and motor cortex stimulation. These results also demonstrate that the initial trial stimulation helps to optimize permanent electrode positions in relation to the optimal functional target that is critical in cases when brain shift is expected. Proposed methodology and novel results open a new direction for development of neuromodulation techniques to control chronic neuropathic pain.


Nutrients ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2681
Author(s):  
Viggiano ◽  
Meccariello ◽  
Santoro ◽  
Secondulfo ◽  
Operto ◽  
...  

The antiepileptic effect of ketogenic diets is acknowledged but its mechanism of action is poorly understood. The present work aimed to evaluate possible effects of a calorie-restricted ketogenic diet (CRKD) on brain growth and angiogenesis in normal prepubertal rats. Two groups of prepubertal rats were fed with a standard diet (group 1) or a CRKD (group 2) for ten weeks. Then, rats were sacrificed and the thickness for the following structures was evaluated by histology: (1) cerebral cortex, (2) deep cerebral white matter, and (3) substantia nigra. The capillary density was also evaluated within: (1) cerebral cortex, (2) dentate gyrus of the hippocampus, (3) periaqueductal grey matter, and (4) substantia nigra. The results showed a smaller thickness of all the areas examined and a reduced capillary density within the cerebral cortex in the CRKD-treated group compared to the control group. These findings suggest an association between reduced angiogenesis within the cerebral cortex and the antiepileptic effects of CRKD.


1973 ◽  
Vol 132 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Martin Reddington ◽  
Richard Rodnight ◽  
Michael Williams

1. The effect of various agents on the turnover of protein-bound phosphorus in respiring slices of cerebral cortex was studied. 2. Confirming previous work turnover was increased by the application of electrical pulses for 10s to the tissue. 3. Turnover was also increased by exposure of the slices for 10min to noradrenaline (0.5mm), 5-hydroxytryptamine (1μm) and histamine (0.1mm). 4. When slices were stimulated by electrical pulses in the presence of histamine the increase in turnover was the sum of the responses given by each agent above, suggesting that different phosphorylating systems were involved. 5. Tetrodotoxin (0.5μm) blocked the increased turnover due to electrical pulses, but not that due to histamine. Tetrodotoxin also prevented the increase in tissue cyclic AMP content caused by the application of electrical pulses. 6. Phosphoprotein turnover was not affected by adenosine, despite the increase in tissue cyclic AMP content given by this agent. 7. Adenosine blocked the phosphoprotein response to histamine, but did not affect the response to electrical pulses. 8. The results are discussed in relation to the hypothesis that the stimulation of protein phosphorus turnover by electrical pulses is secondary to the release of cyclic AMP in the tissue.


1998 ◽  
Vol 26 (03n04) ◽  
pp. 265-274 ◽  
Author(s):  
Ching-Liang Hsieh ◽  
Tsai-Chung Li ◽  
Chien-Yu Lin ◽  
Nou-Ying Tang ◽  
Qwang-Yuen Chang ◽  
...  

Although acupuncture has traditionally used the acupoints formula to treat diseases, the physiological mechanisms involved and the effectiveness of therapy remain unclear. This study investigated the physiological mechanism(s) and response to acupuncture stimulation using the acupoints formula. Scalp-recorded potentials P300 were evoked by auditory stimulation of non-target and target in 13 normal adult volunteers. Latencies and amplitudes were measured. Three assessments were performed in each subject over a period of at least one week. Each assessment was divided into a control period with no acupuncture stimulation, followed by an acupuncture period and then a post-acupuncture period. Acupuncture needles were inserted into the body as follows: 1) non-acupoint: acupuncture needles were inserted 2 cm lateral to both Zusanli acupoints; 2) acupoint: acupuncture needles were inserted into both Zusanli acupoints; 3) acupoints formula: acupuncture needles were inserted into both Zusanli and Shousanli acupoints. Our results showed that both acupoint and acupoints formula assessments resulted in a significant decrease of P300 amplitudes during the acupuncture and post-acupuncture periods. However, there was significant difference in P300 amplitudes in the non-acupoint assessment during these periods. P300 changes in latencies and amplitudes were not significantly different between the acupoint assessment and the acupoints formula assessment. We concluded that acupuncture stimulation of both Zusanli acupoints resulted in a decrease of P300 amplitudes, suggesting the involvement of the cerebral cortex in sensory interaction when simultaneous sensations of the two types are received. No similar changes were observed in the non-acupoint assessment, which have been suggested to be related to so-called acupoint specificity. Results obtained using the acupoints formula were not significantly different from those using acupoints alone. These findings suggested that neuropsychological effects from stimulation of Zusanli acupoints and Shousanli acupoints are different.


Sign in / Sign up

Export Citation Format

Share Document