Effect of the Group II Metabotropic Glutamate Agonist, 2R,4R-APDC, Varies With Age, Layer, and Visual Experience in the Visual Cortex

1999 ◽  
Vol 82 (1) ◽  
pp. 86-93 ◽  
Author(s):  
C. J. Beaver ◽  
Q.-H. Ji ◽  
N. W. Daw
Keyword(s):  
Visual Cortex ◽  
Metabotropic Glutamate Receptors ◽  
Visual Stimulation ◽  
Ocular Dominance ◽  
Visual Response ◽  
Single Neurons ◽  
Metabotropic Glutamate ◽  
Layer 4 ◽  
Group Ii ◽  
Dark Rearing

Group II metabotropic glutamate receptors (mGluR 2/3) are distributed differentially across the layers of cat visual cortex, and this distribution varies with age. At 3–4 wk, mGluR 2/3 receptor immunoreactivity is present in all layers. By 6–8 wk of age, it is still present in extragranular layers (2, 3, 5, and 6) but has disappeared from layer 4, and dark-rearing postpones the disappearance of Group II receptors from layer 4. We examined the physiological effects of Group II activation, to see if these effects varied similarly. The responses of single neurons in cat primary visual cortex were recorded to visual stimulation, then the effect of iontophoresis of 2R,4R-4 aminopyrrolidine-2,4-decarboxylate (2R,4R-APDC), a Group II specific agonist, was observed in animals between 3 wk and adulthood. The effect of 2R,4R-APDC was generally suppressive, reducing both the visual response and spontaneous activity of single neurons. The developmental changes were in agreement with the immunohistochemical results: 2R,4R-APDC had effects on cells in all layers in animals of 3–4 wk but not in layer 4 of animals >6 wk old. Moreover, the effect of 2R,4R-APDC was reduced in the cortex of older animals (>22 wk). Dark-rearing animals to 47–54 days maintained the effects of 2R,4R-APDC in layer 4. The disappearance of Group II mGluRs from layer 4 between 3 and 6 wk of age is correlated with the segregation of ocular dominance columns in that layer, raising the possibility that mGluRs 2/3 are involved in this process.

Activation of metabotropic glutamate receptors has different effects in different layers of cat visual cortex

1997 ◽  
Vol 14 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Silvia N.M. Reid ◽  
Nigel W. Daw
Keyword(s):  
Visual Cortex ◽  
Dicarboxylic Acid ◽  
Glutamate Receptors ◽  
Spontaneous Activity ◽  
Primary Visual Cortex ◽  
Metabotropic Glutamate Receptors ◽  
Visual Response ◽  
Single Neurons ◽  
Metabotropic Glutamate ◽  
Cat Visual Cortex

AbstractSingle neurons were recorded in cat primary visual cortex, and the effect of iontophoresis of the metabotropic glutamate agonist 1S,3R-aminocyclopentane-1.3-dicarboxylic acid (ACPD) was observed. In nearly all cases (41/43), ACPD reduced the visual response. In some cases ACPD also reduced spontaneous activity (24/43), and in other cases ACPD increased spontaneous activity (18/43). Increases were generally seen in infragranular layers (V and VI), and decreases in supragranular layers (II and III). The reduction in the visual response was also largest in supragranular layers. We conclude that activation of metabotropic glutamate receptors has both facilitatory and depressive effects in visual cortex, and the effect depends on the layer of the cell recorded.

Activation of Group III mGluRs increases the activity of neurons in area 17 of the cat

2002 ◽  
Vol 19 (3) ◽  
pp. 355-364 ◽  
Author(s):  
C.J. BEAVER ◽  
Q-H. JI ◽  
X-T. JIN ◽  
N.W. DAW
Keyword(s):  
Visual Cortex ◽  
Spontaneous Activity ◽  
Metabotropic Glutamate Receptors ◽  
Visual Stimulation ◽  
Visual Response ◽  
Area 17 ◽  
Group Iii ◽  
Metabotropic Glutamate

Activation of Group III metabotropic glutamate receptors (mGluRs) by L(+)-2-amino-4-phosphonobutyric acid (L-AP4) has different effects on in vitro slice preparations of visual cortex (Jin & Daw, 1998) as compared with in vivo recordings from somatosensory cortex (Wan & Cahusac, 1995). To investigate the role of Group III mGluRs in the cat visual cortex, in vivo recordings were made of neurons in area 17 of the visual cortex of kittens and adult cats at different ages and the effect of iontophoretic application of L-AP4 (100 mM) was examined. Application of L-AP4 resulted in an increase of the spontaneous activity and visual response of neurons to visual stimulation, the former more than the latter. The effect of L-AP4 was greatest at 3–5 weeks of age with the effect on the visual response declining more rapidly than the effect on spontaneous activity. Consistent with work in rat cortex (Jin & Daw, 1998), the effect of L-AP4 was significantly greater in upper and lower layers than in middle layers. Whole-cell in vitro recordings from slices of rat visual cortex indicated that L-AP4 (50 mM) did not increase the number of spikes elicited by increasing levels of current injections. These results confirm that L-AP4 increases activity in vivo and reasons for the discrepancy with the in vitro results are discussed.

Effect of the Group I Metabotropic Glutamate Agonist DHPG on the Visual Cortex

2001 ◽  
Vol 86 (4) ◽  
pp. 1622-1631 ◽  
Author(s):  
Xiao-Tao Jin ◽  
Christopher J. Beaver ◽  
Qinghua Ji ◽  
Nigel W. Daw
Keyword(s):  
Visual Cortex ◽  
Glutamate Receptors ◽  
Metabotropic Glutamate Receptors ◽  
Visual Response ◽  
Excitatory Effect ◽  
Partial Explanation ◽  
Metabotropic Glutamate ◽  
Cat Visual Cortex ◽  
Group I

Metabotropic glutamate receptors have a variety of effects in visual cortex that depend on the age of the animal, the layer of the cortex, and the group of the receptor. Here we describe these effects for group I receptors, using both in vivo and in vitro preparations. The metabotropic group I glutamate receptor agonist 3,5 dihydroxyphenylglycine (DHPG) potentiates the responses to N-methyl-d-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) in slices of rat visual cortex. It also increases, initially, the visual response in the cat visual cortex. Both these effects are largest at 3–4 wk of age and decline to insignificance by 10 wk of age. Both are also largest in lower layers of cortex, which explains why the facilitatory effects found with the general metabotropic glutamate agonist 1S,3R aminocyclopentane-1,3-dicarboxylic acid (ACPD) are observed only in lower layers. Prolonged application of DHPG in the cat visual cortex, after the initial excitatory effect, produces depression. We also found that DHPG facilitates the NMDA response in fast-spiking cells, which are inhibitory, providing a partial explanation for this. Thus there are multiple effects of group I metabotropic glutamate receptors, which vary with layer and age in visual cortex.

scholarly journals A modulatory effect of the feedback from higher visual areas to V1 in the mouse

2013 ◽  
Vol 109 (10) ◽  
pp. 2618-2631 ◽  
Author(s):  
Roberto De Pasquale ◽  
S. Murray Sherman
Keyword(s):  
Metabotropic Glutamate Receptors ◽  
Metabotropic Glutamate ◽  
Group I ◽  
Layer 4 ◽  
Group I Mglurs ◽  
Group Ii ◽  
Visual Cortical ◽  
Higher Visual Areas ◽  
Brain Slice Preparation ◽  
Feedback Pathway

Using a mouse brain slice preparation, we studied the modulatory effects of a feedback projection from higher visual cortical areas, mostly or exclusively area LM (or V2), on two inputs to layer 4 cells in the first visual area (V1). The two inputs to these cells were geniculocortical and an unspecified intracortical input, possibly involving layer 6 cells. We found that activation of metabotropic glutamate receptors (mGluRs) from stimulation of the feedback projection reduced the evoked excitatory postsynaptic currents of both of these inputs to layer 4 but that this modulation acts in an input-specific way. Reducing the strength of the geniculocortical input in adults involved both presynaptic and postsynaptic group I mGluRs (although in younger animals presynaptic group II mGluRs were also involved), whereas modulation of the intracortical input acted entirely via postsynaptic group II mGluRs. These results demonstrate that one of the effects of this feedback pathway is to control the gain of geniculocortical transmission.

scholarly journals HDAC and HAT Inhibitors Differently Affect Analgesia Mediated by Group II Metabotropic Glutamate Receptors

2014 ◽  
Vol 10 ◽  
pp. 1744-8069-10-68 ◽  
Author(s):  
Magda Zammataro ◽  
Maria Angela Sortino ◽  
Carmela Parenti ◽  
Robert W Gereau ◽  
Santina Chiechio
Keyword(s):  
Glutamate Receptors ◽  
Metabotropic Glutamate Receptors ◽  
Metabotropic Glutamate ◽  
Group Ii
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