Abstract
Transient moderate hypoxia has been previously shown to exert a potent protective role to subsequently applied convulsant drugs. We now investigated neuropeptide Y and somatostatin immunoreactivities seven days after moderate hypoxia (9% O2 in N2 for two times 8 h) in the hippocampus of the rat. A slight reduction of somatostatin immunoreactive cells was observed in the hilus of the dorsal and ventral hippocampus. At the same time, the total number of neuropeptide Y immunoreactive neurons was increased in this area due to a pronounced increase in staining of presumable basket cells. There was also increased staining of neuropeptide Y positive fibers in the outer molecular layer. Our data suggest activation of neuropeptide Y containing interneurons after a moderate or a mild transient hypoxia. Activation of these inhibitory neurons may contribute to the protective effect of this treatment.
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Amano S, Obata T, Hazama F, Kashiro N, Shimada M (1990) Hypoxia prevents seizures and neuronal damages of the hippocampus induced by kainic acid in rats. Brain Res 523: 121–126
Bellmann R, Widmann R, Olenik C, Meyer DK, Maas D, Marksteiner J, Sperk G (1991) Enhanced rate of expression and biosynthesis of neuropeptide Y after kainic acid induced seizures. J Neurochem 56: 525–530
Bortolotto ZA, Heim C, Sieklucka M, Block F, Sontag K-H, Cavalheiro EA (1991) Effects of bilateral clamping of carotis arteries on hippocampal kindling in rats. Physiol Behav 49: 667–671
Brooks PA, Kelly JS, Allen JM, Smith DA, Stone TW (1987) Direct excitatory effect of neuropeptide Y (NPY) on rat hippocampal neurons in vitro. Brain Res 408: 295–298
Deller T, Leranth C (1990) Synaptic connections of neuropeptide Y (NPY) immunoreactive neurons in the hilar area of the rat hippocampus. J Comp Neurol 300: 433–447
Heim C, Bortolotto ZA, Cavalheiro EA, Sontag K-H (1991) Transient occlusion of carotid arteries decreases susceptibility to pilocarpine seizures. Brain Res 544: 253–259
Johansen FF, Zimmer J, Diemer NH (1987) Early loss of somatostatin neurons in dentate hilus after cerebral ischemia in the rat precedes CA-1 pyramidal cell loss. Acta Neuropathol 73: 110–114
Jones EG, Hendry SHC (1986) Colocalization of GABA and neuropeptides in neocortical neurons. Trends Neurosci 103: 3
Kelly ME, McIntyre DC (1994) Hippocampal kindling protects several structures from the neuronal damage resulting from kainic acid-induced status epilepticus. Brain Res 634: 245–256
Köhler C, Eriksson LG, Davies S, Chan-Palay V (1987) Co-localization of neuropeptide tyrosine and somatostatin immunoreactivity in neurons of individual subfields of the rat hippocampal region. Neurosci Lett 78: 1–6
Köhler C, Eriksson LG, Davies S, Chan-Palay V (1986) Neuropeptide Y innervation of the hippocampal region in the rat and monkey brain. J Comp Neurol 244: 384–400
Kosaka T, Wu J-Y, Benoit R (1988) GABAergic neurons containing somatostatin-like immunoreactivity in the rat hippocampus and dentate gyrus. Exp Brain Res 71: 388–398
Paxinos G, Watson C (1986) The rat brain in stereotaxic coordinates. Academic Press, Sydney
Pérez J, Vezzani A, Civenni G, Tutka P, Rizzi M, Schupbach E, Hoyer D (1995) Functional effects of D-Phe-c(Cys-Tyr-D-Trp-Lys-Val-Cys)-Trp-NH2 and differential changes in somatostatin receptor messenger RNAs, binding sites and somatostatin release in kainic acid-treated rats. Neuroscience 65: 1087–1097
Pohle W, Rauca C (1994) Hypoxia protects against the neurotoxicity of kainic acid. Brain Res 644: 297–304
Rauca C, Rütbrich H-L (1995) Moderate hypoxia reduces pentylenetetrazol-induced seizures. Naunyn-Schmiedeberg's Arch Pharmacol 351: 261–267
Rizzi M, Monno A, Samanin R, Sperk G, Vezzani A (1993) Electrical kindling of the hippocampus is associated with functional activation of neuropeptide Y-containing neurons. Eur J Neurosci 5: 1534–1538
Schwarzer C, Sperk G (1995) Hippocampal granule cells express glutamic acid decarboxylase-67 after limbic seizures in the rat. Neuroscience 69: 705–709
Schwarzer C, Sperk G, Samanin R, Rizzi M, Gariboldi M, Vezzani A (1996) Lasting changes in somatostatin, neuropeptide Y, neurokinin B, cholecystokinin-immunoreactivity and their mRNA expression in kindling epileptogenesis. Brain Res Rev (in press)
Schwarzer C, Williamson JM, Lothman EW Vezzani A, Sperk G (1995) Somatostatin, neuropeptide Y, neurokinin B and cholecystokinin immunoreactivity in two chronic models of temporal lobe epilepsy. Neuroscience 69: 831–845
Sieklucka M, Bortolotto ZA, Heim C, Block F, Sontag K-H (1991) Decreased susceptibility to seizures induced by bicuculine after transient bilateral clamping of the carotic arteries in rats. J Neural Transm Gen Sect 83: 127–137
Sieklucka M, Heim C, Block F, Sontag K-H (1992) Transient reduction of cerebral blood flow leads to long-lasting decreases in bicuculline induced seizures. J Neural Transm Gen Sect 88: 87–94
Sloviter RS (1987) Decreased hippocampal inhibition and a selective loss of interneurons in experimental epilepsy. Science 235: 73–76
Somogyi P, Hodgson AJ, Smith AD, Nunzi GM, Gorio A, Wu JY (1984) Different populations of GABAergic neurons in the visual cortex and hippocampus of cat containing somatostatin- or cholecystokinin-immunoreactive material. J Neurosci 4: 2590–2603
Sperk G, Marksteiner J, Gruber B, Bellmann R, Mahata M, Ortler M (1992) Functional changes in neuropeptide Y and somatostatin containing neurons induced by limbic seizures in the rat. Neuroscience 50: 831–846
Sperk G, Widmann R (1985) Somatostatin precursor in the rat striatum: changes after local injection of kainic acid. J Neurochem 45: 1441–1447
Sternberger L (1979) Immunohistochemistry, 2nd edn. Wiley, New York
Vezzani A, Serafini R, Stasi MA, Vigano G, Rizzi M, Samanin R (1991) Somatostatin and its octapeptide analog SMS 201–995 modulate seizures induced by quinolinic and kainic acids differently in the rat hippocampus. Neuropharmacology 30: 345–352
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Schwarzer, C., Sperk, G., Rauca, C. et al. Neuropeptide Y and somatostatin immunoreactivity in the rat hippocampus after moderate hypoxia. Naunyn-Schmiedeberg's Arch Pharmacol 354, 67–71 (1996). https://doi.org/10.1007/BF00168708
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DOI: https://doi.org/10.1007/BF00168708