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Disruption Of Hippocampal Multisynaptic Networks By General Anesthetics., Min-Ching Kuo, L Stan Leung

Physiology and Pharmacology Publications

BACKGROUND: Previous studies showed that synaptic transmission is affected by general anesthetics, but an anesthetic dose response in freely moving animals has not been done. The hippocampus provides a neural network for the evaluation of isoflurane and pentobarbital on multisynaptic transmission that is relevant to memory function.

METHODS: Male Long-Evans rats were implanted with multichannel and single electrodes in the hippocampus. Spontaneous local field potentials and evoked field potentials were recorded in freely behaving rats before (baseline) and after various doses of isoflurane (0.25 to 1.5%) and sodium pentobarbital (10 mg/kg intraperitoneal).

RESULTS: Monosynaptic population excitatory postsynaptic potentials at the …

Development Of New Methods To Investigate The Role Of The Avian Hippocampus In Memory Formation In Brown-Headed Cowbirds, Madeleine Ir Brodbeck

Electronic Thesis and Dissertation Repository

The hippocampus is known to participate in a variety of cognitive functions in humans, non-human primates, rodents, and birds. A great deal of previous research on the avian hippocampus has examined its role in spatial memory. A question regarding avian hippocampal function that remains unanswered is, what is its role in encoding, retention, and retrieval of spatial information? To answer this question I, 1) describe spatial and non-spatial versions of a touchscreen task and my attempts to determine if the spatial version of the task is hippocampus dependent, and 2) describe the development of an implantable cryoloop which can be …

Winter Warming Affects The Onset Of Reproduction But Not Cognition Or The Hippocampus In Black-Capped Chickadees (Poecile Atricapillus), Robert J. Martin

Electronic Thesis and Dissertation Repository

The effects of overwinter temperature on behaviour and cognition, hippocampal volume, and reproductive timing were studied in Black-capped chickadees (Poecile atricapillus). I hypothesized that overwinter temperature would have varied effects for Black-capped chickadees that overwinter in northern climates. I found that temperature had no effect on behaviour and cognition, or hippocampal volume, but temperature did influence reproductive timing. Birds that experienced warmer winter conditions had significantly more developed gonads than birds that experienced colder conditions. These results suggest that while birds are clearly sensitive to ambient winter temperature, temperature only modulates some processes and not all. These studies …

Hippocampal Neurogenesis And Volume In Migrating And Wintering Semipalmated Sandpipers (Calidris Pusilla)., Nara Gyzely De Morais Magalhães, Cristovam Guerreiro Diniz, Daniel Guerreiro Diniz, Ediely Pereira Henrique, Patrick Douglas Corrêa Pereira, Isis Ananda Matos Moraes, Mauro André Damasceno De Melo, David Francis Sherry, Cristovam Wanderley Picanço Diniz

Brain and Mind Institute Researchers' Publications

Long distance migratory birds find their way by sensing and integrating information from a large number of cues in their environment. These cues are essential to navigate over thousands of kilometers and reach the same breeding, stopover, and wintering sites every year. The semipalmated sandpiper (Calidris pusilla) is a long-distance migrant that breeds in the arctic tundra of Canada and Alaska and winters on the northeast coast of South America. Its fall migration includes a 5,300-kilometer nonstop flight over the Atlantic Ocean. The avian hippocampus has been proposed to play a central role in the integration of multisensory spatial information …

Are There Place Cells In The Avian Hippocampus?, David F Sherry, Stephanie L Grella, Mélanie F Guigueno, David J White, Diano F Marrone

Brain and Mind Institute Researchers' Publications

Birds possess a hippocampus that serves many of the same spatial and mnemonic functions as the mammalian hippocampus but achieves these outcomes with a dramatically different neuroanatomical organization. The properties of spatially responsive neurons in birds and mammals are also different. Much of the contemporary interest in the role of the mammalian hippocampus in spatial representation dates to the discovery of place cells in the rat hippocampus. Since that time, cells that respond to head direction and cells that encode a grid-like representation of space have been described in the rat brain. Research with homing pigeons has discovered hippocampal cells, …

Are There Place Cells In The Avian Hippocampus?, David F Sherry, Stephanie L Grella, Mélanie F Guigueno, David J White, Diano F Marrone

Psychology Publications

Birds possess a hippocampus that serves many of the same spatial and mnemonic functions as the mammalian hippocampus but achieves these outcomes with a dramatically different neuroanatomical organization. The properties of spatially responsive neurons in birds and mammals are also different. Much of the contemporary interest in the role of the mammalian hippocampus in spatial representation dates to the discovery of place cells in the rat hippocampus. Since that time, cells that respond to head direction and cells that encode a grid-like representation of space have been described in the rat brain. Research with homing pigeons has discovered hippocampal cells, …