Abstract
The rat is a nocturnal animal and uses its vibrissae extensively to navigate its environment. The vibrissae are linked to a highly organized part of the sensory cortex, called the barrel cortex which contains spiny neurons that receive whisker specific thalamic input and distribute their output mainly within the cortical column. The aim of the present study was to develop a method to evaluate glutamate receptor function in the rat barrel cortex. Long Evans rats (90 – 160g) were killed by cervical dislocation and decapitated. The brain was rapidly removed, cooled in a continuously oxygenated, ice-cold Hepes buffer (pH 7.4) and sliced using a vibratome to produce 0.35mm slices. The barrel cortex was dissected from slices corresponding to 8.6 to 4.8mm anterior to the interaural line and divided into rostral, middle and caudal regions. Depolarization-induced uptake of 45Ca2+ was achieved by incubating test slices in a high K+ (62.5mM) buffer for 2 minutes at 35°C. Potassium-stimulated uptake of 45Ca2+ into the rostral region was significantly lower than into middle and caudal regions of the barrel cortex. Glutamate had no effect. NMDA significantly increased uptake of 45Ca2+ into all regions of the barrel cortex. The technique is useful in determining NMDA receptor function and will be applied to study differences between spontaneously hypertensive rats (SHR) that are used as a model for attention deficit disorder and their normotensive control rats.
Similar content being viewed by others
REFERENCES
Aitken, P.G., Breese, G.R., Dudek, F.F., Edwards, F., Espanol, M.T., Larkman, P.M., Lipton, P., Newman, G.C., Nowak, T.S., Panizzon, K.L., Raley-Susman, K.M., Reid, K.H., Rice, M.E., Sarvey, J.M., Schoepp, D.D., Segal, M., Taylor, C.P., Teyler, and T.J., Voulalas (1995). Preparative methods for brain slices: a discussino. J. Neurosci. Methods 59:139-149.
Burnashev, N. (1996). Calcium permeability of glutamate gated channels in the central nervous system. Current opinion in Neurobiology 6:311-317.
Chazot, P.L., Coleman, S.K., Cik, M., and Stephenson, F.A. (1994). Molecular characterization of N-Methyl-D-aspartate receptors expressed in mammalian cells yields evidence for the coexistence of three subunit types within a discrete receptor molecule. J. Biol. Chem. 269:24403-24409.
Egger, V., Feldmeyer, D., and Sakmann, B. (1999). Coincidence detection and changes of synaptic efficacy in spiny stellate neurons in rat barrel cortex. Nature Neuroscience 2:1098-1105.
Feldman, D., Sherin, J.E., Press, W.A., and Bear, M.F. (1990). N-methyl-D-aspartate evoked calcium uptake by kitten visual cortex maintained in vitro. Exp. Brain Res. 80:252-259.
Feldmeyer, D., and Sakmann, B. (2000). Synaptic efficacy and reliability of excitatory connections between the principal neurons of the output layer (layer 5) of the neocortex. J. Physio. 523:31-39.
Feldmeyer, D., Egger, V., Lubke, J., and Sakmann, B. (1999). Reliable synaptic connections between pairs of excitatory layer 4 neurons within a single ‘barrel’ of a developing rat somatosensory cortex. J. Physiol. 521:169-190.
Herrera-Marschitz, M., You, Z.B., Goiny, M., Meana, J.L., Silveira, R., Godukhin, O.V., Chen, Y., Espinoza, S., Petterson, E., Loidl, C.F., Lubec, G., Anderson, K., Nylander, I., Terenius, L. and Ungerstedt, U. (1996). On the origin of extracellular glutamate levels monitored in the basal ganglia of the rat by in vivo microdialysis. J. Neurochem 66:1726-1735.
Jaarsma, D., Sebens, J.B., and Korf, J. (1991). Localization of NMDA and AMPA receptors in rat barrel field. Neurosci. Lett. 133:233-236.
Keller, A. (1995). Synaptic organization of the barrel cortex. Cerebral Cortex 11:221-262.
Lipton, P., Aitken, P.G., Dudek, F.F., Eskessen, K., Espano, I M.T., Ferchmin, P.A., Kelly, J.B., Kreisman, N.R., Leybaert, L., Newman, G.C., Panizzon, K.L., Payne, R.S., Phillips, P., Raley-Susman, K.M., Rice, M.E., Santamaria, R., Sarvey, J.M., Schurr, A., Segal, M., Taylor, C.P., Teyler, T.J., Vasilenko, V.Y., Veregge, S., Wu, S.H., and Wallis, R. Making the best of brain slices: comparing preparative methods. J. Neurosci. Methods 59:151-156.
Miller, G.L. (1959). Protein determination for large number of samples. Analytical Chemistry 31:964.
Oosterlaan, J., and Sergeant, J.A. (1998). Response inhibition and response re-engagement in attention-deficit/hyperactivity disorder, disruptive, anxious and normal children. Behav. Brain Res. 94:33-43.
Paxinos, G., and Watson, C. (1986). The rat brain in stereotaxic coordinates. Academic Press, New York.
Sagvolden, T., and Sergeant, J.A. (1998). Attention deficit/hyperactivity disorder-from brain dysfunctions to behavior. Behav. Brain Res. 94:1-10.
Sagvolden, T., Wultz, B., Moser, E.I., Moser, M.B. and Morkid, L. (1989). Results from a comparative neuropsychological research program indicate altered reinforcement mechanisms in children with ADD. In: T. Sagvolden and T. Archer (eds), Attention deficit disorder: Clinical and basic research, Lawrence Erlbaum Associates, Hillsdale, New Jersey, U.S.A. pp261-286.
Schamme, M., and Hemmings, Jr., M.D. (1995). Inhibition by volatile Anaesthetics of endogenous glutamate release from synaptosomes by a presynaptic mechanism. Anesthesiology 82:1406-1416.
Simonato, M., Jope, R. S., Bianchi, C., and Beani, L. (1989). Lack of excitatory amino acid-induced effects on calcium fluxes measured with 45Ca2+ in rat cerebral cortex synaptosomes. Neurochemical Research 14:677-682.
Solanto, M.V. (1998). Neuropsychopharmacological mechanisms of stimulant drug action in attention deficit hyperactivity disorder: a review and integration. Behav. Brain Res. 94:127-152.
Woolsey, T.A., and Van der Loos, H. (1970). The structural organisation of layer IV in the somatosensory region (SI) of mouse cerebral cortex. Brain Research 17:205-242.
Zigmond, J.M., Bloom, F.E., Landis, S.C., Roberts, J.L., and Squire, L.R., (1999). Fundamental Neuroscience. Academic Press.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lehohla, M., Russell, V., Kellaway, L. et al. Development of a Method to Evaluate Glutamate Receptor Function in Rat Barrel Cortex Slices. Metab Brain Dis 15, 305–314 (2000). https://doi.org/10.1023/A:1011127309582
Issue Date:
DOI: https://doi.org/10.1023/A:1011127309582