Effects of glycolytic metabolites on preservation of high energy phosphate level and synaptic transmission in the granule cells of guinea pig hippocampal slices

1995 ◽  
Vol 51 (3) ◽  
pp. 213-216 ◽  
Author(s):  
T. Kanatani ◽  
K. Mizuno ◽  
Y. Okada
Keyword(s):  
Guinea Pig ◽  
Synaptic Transmission ◽  
Granule Cells ◽  
Hippocampal Slices ◽  
High Energy ◽  
Phosphate Level ◽  
High Energy Phosphate

K-dependent inhibition in the dentate-CA3 network of guinea pig hippocampal slices

1992 ◽  
Vol 68 (5) ◽  
pp. 1548-1557 ◽  
Author(s):  
U. Misgeld ◽  
M. Bijak ◽  
H. Brunner ◽  
K. Dembowsky
Keyword(s):  
Guinea Pig ◽  
Granule Cells ◽  
Hippocampal Slices ◽  
Granule Cell Layer ◽  
Postsynaptic Potentials ◽  
Burst Discharge ◽  
Mossy Cells ◽  
Discharge Activity ◽  
Dependent Inhibition ◽  
Hilar Neurons

1. The occurrence of potassium-dependent inhibitory postsynaptic potentials (K-IPSPs) in relation to burst discharges induced by 4-aminopyridine (4-AP; 30 microM) was studied in CA3, granule and hilar neurons in guinea pig hippocampal slices with the use of paired extra- and/or intracellular recording. 2. Slow small (2-5 mV) and large (up to 30 mV) K-IPSPs were observed in CA3, granule and in some hilar neurons during 4-AP applications in the presence of blockers for fast synaptic transmission, picrotoxin (50 microM), and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 5-10 microM). Amplitudes of K-IPSPs were linearly related to voltage, and they reversed in sign close to -100 mV, as expected for synaptic potentials generated by an increase in K-conductance. 3. In CA3 neurons, 4-AP applied in the presence of picrotoxin elicited burst discharges and K-IPSPs. CNQX blocked the burst discharge activity and increased the amplitude of K-IPSPs. 4. In granule cells, 4-AP applied in the presence of picrotoxin elicited K-IPSPs and only inconsistently small excitatory postsynaptic potentials (EPSPs). The EPSPs were blocked by CNQX, but CNQX application did not affect the K-IPSPs. However, in granule cells it could be observed that blockade of Cl-inhibition by picrotoxin in the presence of CNQX increased the amplitude of K-IPSPs. 5. In hilar neurons, 4-AP applied in the presence of picrotoxin elicited mainly burst discharges. CNQX blocked the burst discharges only in a few cells. In most hilar neurons K-IPSPs were observed at the beginning of the 4-AP effect, but subsequently K-IPSPs were replaced by burst discharges. 6. To determine the type of cells that burst in picrotoxin and 4-AP, neurons were stained intracellularly with horseradish peroxidase. Neurons stained in the granule cell layer did not burst and were morphologically identified as granule cells. Neurons stained in the hilar region burst and were nonpyramidal, nongranule cells. Bursting cells stained in the CA3 area were all pyramidal cells. 7. The hilar neurons varied considerably in size and dendritic organization. They could be classified as aspiny and spiny cells, the latter including mossy cells. 8. We conclude that K-dependent inhibition may explain the long-lasting IPSPs observed in in vivo recordings from hippocampal cells. In a hippocampal lamella, burst discharge activity of hilar neurons including presumed excitatory mossy cells is associated with inhibition of granule cells.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals The effect of electrical stimulation on the incorporation of l-[U-14C]valine into the protein of chopped tissue from guinea-pig cerebral cortex

1970 ◽  
Vol 118 (5) ◽  
pp. 791-800 ◽  
Author(s):  
C. T. Jones ◽  
P. Banks
Keyword(s):  
Cerebral Cortex ◽  
Electrical Stimulation ◽  
Guinea Pig ◽  
High Energy ◽  
Initial Increase ◽  
Nuclear Fraction ◽  
High Energy Phosphate ◽  
Experimental Conditions ◽  
Relative Contribution ◽  
Energy Dependent

1. Chopped tissue from guinea-pig cerebral cortex carried out an energy-dependent incorporation of [14C]valine into protein. 2. At all times studied the nuclear fraction of the homogenized tissue accounted for about 25% of the total labelled protein. 3. Electrical stimulation at first increased, but subsequently decreased, the rate of incorporation of [14C]valine into protein of the chopped tissue. 4. The initial increase in the incorporation of [14C]valine into protein occurred in the nuclear fraction. At later times electrical stimulation decreased the incorporation into all the subcellular fractions, but the relative contribution of the nuclear fraction to the total labelled protein increased. 5. These changes are discussed in relation to the changes in the rates of respiration, glycolysis, high-energy phosphate content and intracellular Na+ and K+ concentrations, which were measured under the same experimental conditions as those used to study protein synthesis.

Actions of MPTP and MPP+ on synaptic transmission in guinea-pig hippocampal slices

1987 ◽  
Vol 96 (2) ◽  
pp. 289-298 ◽  
Author(s):  
M. Galvan ◽  
A. Kupsch ◽  
G. ten Bruggencate
Keyword(s):  
Guinea Pig ◽  
Synaptic Transmission ◽  
Hippocampal Slices

Brevetoxin depresses synaptic transmission in guinea pig hippocampal slices

1993 ◽  
Vol 31 (1-2) ◽  
pp. 201-207 ◽  
Author(s):  
James P. Apland ◽  
Michael Adler ◽  
Robert E. Sheridan
Keyword(s):  
Guinea Pig ◽  
Synaptic Transmission ◽  
Hippocampal Slices

Altered synaptic transmission in dentate gyrus of rats reared in complex environments: evidence from hippocampal slices maintained in vitro

1986 ◽  
Vol 55 (4) ◽  
pp. 739-750 ◽  
Author(s):  
E. J. Green ◽  
W. T. Greenough
Keyword(s):  
Synaptic Transmission ◽  
Dentate Gyrus ◽  
Granule Cell ◽  
Granule Cells ◽  
Cell Layer ◽  
Molecular Layer ◽  
Hippocampal Slices ◽  
Granule Cell Layer ◽  
Complex Environments ◽  
Rearing Environment

Pre- and postsynaptic responses to activation of medial perforant path (MPP) axons were examined in hippocampal slices taken from rats reared for 3-4 wk in relatively complex (EC) or individual cage (IC) environments. Three types of extracellular field potentials were recorded in the infrapyramidal blade of the dentate gyrus: 1) granule cell population spikes (PSs), which reflect the number and synchrony of discharging granule cells (2), 2) population excitatory postsynaptic potentials (EPSPs), which reflect the amount of excitatory synaptic current flow into dendrites (28), and 3) presynaptic fiber volleys (FVs), which reflect the number of activated axons (28). Stimulation of the MPP evoked significantly larger PSs in slices taken from EC rats. There was no significant effect of rearing environment on PS/EPSP relationships. The slopes of EPSPs recorded at the site of synaptic activation in the dentate molecular layer and at the major current source in the dentate granule cell layer were significantly greater in slices taken from EC rats. The presynaptic FV was recorded at the site of synaptic activation in the molecular layer. FV amplitude did not differ significantly as a function of rearing environment. To examine possible differences in tissue impedance, granule cells were activated by stimulating granule cell axons in the dentate hilus and recording the antidromic PS in the granule cell layer. Antidromic PS amplitude was not significantly affected by rearing environment. The relative permanence of the experience-dependent alterations in synaptic transmission was assessed by comparing slices taken from rats that had been reared for 4 wk in complex environments followed by 3-4 wk in individual cages with those from rats reared for 7-8 wk in individual cages. There were no significant differences in MPP synaptic transmission between these groups of animals. The results suggest that experience in a relatively complex environment is associated with greater MPP synaptic transmission arising from an increased synaptic input to granule cells; the greater MPP synaptic transmission associated with behavioral experience can occur independent of behavioral state, influences from extrahippocampal brain regions and intrahippocampal inhibitory activity; and the experience-dependent synaptic alterations in the dentate gyrus are transient, in contrast to experience-dependent morphological alterations described in occipital cortex. The possible relationship of these alterations to the phenomenon of long-term enhancement is discussed.

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