Functional relationship between forebrain cholinergic projections and somatostatin neurons in the rat

The two neuron types that initially degenerate with Alzheimer's Disease are the cholinergic projections from the septum to the hippocampus and from the substantia innominata to the cortex, and the somatostatinergic neurons in the hippocampus and cortex. The functional relationship between these...

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Main Author: Perry, Theresa Fried
Other Authors: Veterinary Medical Sciences
Format: Others
Language:en
Published: Virginia Tech 2014
Subjects:
Online Access:http://hdl.handle.net/10919/41603
http://scholar.lib.vt.edu/theses/available/etd-03142009-040550/
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spelling ndltd-VTETD-oai-vtechworks.lib.vt.edu-10919-416032021-10-01T05:52:50Z Functional relationship between forebrain cholinergic projections and somatostatin neurons in the rat Perry, Theresa Fried Veterinary Medical Sciences LD5655.V855 1990.P449 Acetylcholine -- Research GABA -- Research Neural transmission -- Regulation Neurotransmitters -- Research Rats -- Physiology Somatostatin -- Research The two neuron types that initially degenerate with Alzheimer's Disease are the cholinergic projections from the septum to the hippocampus and from the substantia innominata to the cortex, and the somatostatinergic neurons in the hippocampus and cortex. The functional relationship between these two types of neurons was investigated using folic acid, a neuro-excitant, and cysteamine, a somatostatin depleter. Folic acid causes a neuron to fire at a much higher rate than normal (Spector, 1971). Folic acid was injected into either the septum or the substantia innominata, and the long-term effect of the resulting acute hyperactivity of the cholinergic neurons on somatostatin neurons was measured as somatostatin-like immunoreactivity in the hippocampus and cortex. Glutamic acid decarboxylase activity, a marker for gamma-amino butyric acid (GABA) neurons, was also measured because it has been shown to decrease in the cortex after injection of folic acid into the substantia innominata. The administration of folic acid to the cholinergic neurons did not have a significant long-term effect on somatostatin-like immunoreactivity nor glutamic acid decarboxylase activity; therefore, a hyperactivity of the cholinergic neurons did not result in degeneration of GABAergic nor somatostatinergic neurons. Cysteamine causes a short-term depletion of somatostatin. Cysteamine was injected subcutaneously and the effect of an acute decrease of brain somatostatin on the cholinergic neurons was studied by measuring high affinity choline uptake, an indicator of cholinergic activity. Administration of cysteamine had no measured effect on high affinity choline uptake in the hippocampus or frontal cortex; therefore, a depletion of somatostatin did not effect cholinergic activity. The assay for high affinity choline uptake was tested by injection of pentobarbital, a drug known to decrease high affinity choline uptake. We detected a decrease in high affinity choline uptake after pentobarbital administration, indicating that if cysteamine were decreasing high affinity choline uptake, the assay would have detected it. Master of Science 2014-03-14T21:31:40Z 2014-03-14T21:31:40Z 1990 2009-03-14 2009-03-14 2009-03-14 Thesis Text etd-03142009-040550 http://hdl.handle.net/10919/41603 http://scholar.lib.vt.edu/theses/available/etd-03142009-040550/ en OCLC# 23123335 LD5655.V855_1990.P449.pdf In Copyright http://rightsstatements.org/vocab/InC/1.0/ vi, 88 leaves BTD application/pdf application/pdf Virginia Tech
collection NDLTD
language en
format Others
sources NDLTD
topic LD5655.V855 1990.P449
Acetylcholine -- Research
GABA -- Research
Neural transmission -- Regulation
Neurotransmitters -- Research
Rats -- Physiology
Somatostatin -- Research
spellingShingle LD5655.V855 1990.P449
Acetylcholine -- Research
GABA -- Research
Neural transmission -- Regulation
Neurotransmitters -- Research
Rats -- Physiology
Somatostatin -- Research
Perry, Theresa Fried
Functional relationship between forebrain cholinergic projections and somatostatin neurons in the rat
description The two neuron types that initially degenerate with Alzheimer's Disease are the cholinergic projections from the septum to the hippocampus and from the substantia innominata to the cortex, and the somatostatinergic neurons in the hippocampus and cortex. The functional relationship between these two types of neurons was investigated using folic acid, a neuro-excitant, and cysteamine, a somatostatin depleter. Folic acid causes a neuron to fire at a much higher rate than normal (Spector, 1971). Folic acid was injected into either the septum or the substantia innominata, and the long-term effect of the resulting acute hyperactivity of the cholinergic neurons on somatostatin neurons was measured as somatostatin-like immunoreactivity in the hippocampus and cortex. Glutamic acid decarboxylase activity, a marker for gamma-amino butyric acid (GABA) neurons, was also measured because it has been shown to decrease in the cortex after injection of folic acid into the substantia innominata. The administration of folic acid to the cholinergic neurons did not have a significant long-term effect on somatostatin-like immunoreactivity nor glutamic acid decarboxylase activity; therefore, a hyperactivity of the cholinergic neurons did not result in degeneration of GABAergic nor somatostatinergic neurons. Cysteamine causes a short-term depletion of somatostatin. Cysteamine was injected subcutaneously and the effect of an acute decrease of brain somatostatin on the cholinergic neurons was studied by measuring high affinity choline uptake, an indicator of cholinergic activity. Administration of cysteamine had no measured effect on high affinity choline uptake in the hippocampus or frontal cortex; therefore, a depletion of somatostatin did not effect cholinergic activity. The assay for high affinity choline uptake was tested by injection of pentobarbital, a drug known to decrease high affinity choline uptake. We detected a decrease in high affinity choline uptake after pentobarbital administration, indicating that if cysteamine were decreasing high affinity choline uptake, the assay would have detected it. === Master of Science
author2 Veterinary Medical Sciences
author_facet Veterinary Medical Sciences
Perry, Theresa Fried
author Perry, Theresa Fried
author_sort Perry, Theresa Fried
title Functional relationship between forebrain cholinergic projections and somatostatin neurons in the rat
title_short Functional relationship between forebrain cholinergic projections and somatostatin neurons in the rat
title_full Functional relationship between forebrain cholinergic projections and somatostatin neurons in the rat
title_fullStr Functional relationship between forebrain cholinergic projections and somatostatin neurons in the rat
title_full_unstemmed Functional relationship between forebrain cholinergic projections and somatostatin neurons in the rat
title_sort functional relationship between forebrain cholinergic projections and somatostatin neurons in the rat
publisher Virginia Tech
publishDate 2014
url http://hdl.handle.net/10919/41603
http://scholar.lib.vt.edu/theses/available/etd-03142009-040550/
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