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The effects of undernutrition during early life on neuron numbers in the rat brain
WS4-B2-1-05
THE EFFECTS OF UNDERNUTRITION DURING EARLY LIFE ON NEURON NUMBERS IN THE RAT BRAIN. K. S. BEDI Department of Anatomical Sciences, University of Queensland, St. Lucia, Queensland 4072, AUSTRALIA. Undernutrition during early life is known to cause deficits and distortions of brain structure although it has remained uncertain whether or not this includes a diminution of the total numbers of neurons. Recent advances in stereological techniques have made it possible to obtain unbiased estimates of total numbers of cells in well defined biological structures. These methods have been utilised in studies to determine the effects of varying periods of undernutrition during early life on the numbers of neurons in various regions of the rat brain. The regions examined so far have included the cerebellum, the dentate gyrus, the olfactory bulbs and the cerebral cortex. The only region to show, unequivocally, that a period of undernutrition during early life causes a deficit in the numbers of neurons was the dentate gyrus. It was found that 212-day-old well-fed control rats had about 834 thousand granule cell neurons in the dentate gyrus whereas previously undernourished rats of the same age had between 5 0 0 - 6 0 0 thousand granule cell neurons. The difference was statistically significant.
WS4-B2-2-01 DOES RIGHT ANTERIORCINGULATEGYRUSMOTIVATELEFTWARD VISUAL EXPLORATION? H. Kubo, S. Irino, K. Hamaguchi Department of Neurology, Saitama Medical School, Saitama, Japan Objective: On visual exploration tasks, neglect patients are known to exhibit different performance when another response manner is requested. We have already reported that some neglect patients performed significantly better by manual canceling than by reading aloud on a visual exploration task for letters, and that the motivational difference was considered to underlie the difference of performances. The aim of this presentation is to report the performances of a neglect patient having a lesion involving right anterior cingulate gyrus, and discuss the role of anterior cingulate gyrus, towhich the motivational role has been hypothesized. Patient: This 76-year-old woman suffered a subarachnoid hemorrhage seven months previously. After an operation to the anterior communicating artery aneurysm, she had left hemiparesis, and remained in abulic state of mute and motionless until the bromocriptin treatment was started five months later. As her abulia improved gradually, left hemispatial neglect appeared. Method: We prepared a visual exploration task with 44 hiragana letters in apparently random distribution among 44 alphabet foils and presented in front of the midline of t~e patient's body. We requested the patient to read aloud or to cancel all the hiragana letters only. These procedures were carried out in a order of reading - canceling - canceling reading. Then we compared the total number of the errors caused by hemispatial neglect in each response manner. Result: She neglected 19 targets in reading procedure, while the neglect was significantly improved to 2 targets in manual canceling (P
253
THE EFFECTS OF UNDERNUTRITION DURING EARLY LIFE ON NEURON NUMBERS IN THE RAT BRAIN. K. S. BEDI Department of Anatomical Sciences, University of Queensland, St. Lucia, Queensland 4072, AUSTRALIA. Undernutrition during early life is known to cause deficits and distortions of brain structure although it has remained uncertain whether or not this includes a diminution of the total numbers of neurons. Recent advances in stereological techniques have made it possible to obtain unbiased estimates of total numbers of cells in well defined biological structures. These methods have been utilised in studies to determine the effects of varying periods of undernutrition during early life on the numbers of neurons in various regions of the rat brain. The regions examined so far have included the cerebellum, the dentate gyrus, the olfactory bulbs and the cerebral cortex. The only region to show, unequivocally, that a period of undernutrition during early life causes a deficit in the numbers of neurons was the dentate gyrus. It was found that 212-day-old well-fed control rats had about 834 thousand granule cell neurons in the dentate gyrus whereas previously undernourished rats of the same age had between 5 0 0 - 6 0 0 thousand granule cell neurons. The difference was statistically significant.
WS4-B2-2-01 DOES RIGHT ANTERIORCINGULATEGYRUSMOTIVATELEFTWARD VISUAL EXPLORATION? H. Kubo, S. Irino, K. Hamaguchi Department of Neurology, Saitama Medical School, Saitama, Japan Objective: On visual exploration tasks, neglect patients are known to exhibit different performance when another response manner is requested. We have already reported that some neglect patients performed significantly better by manual canceling than by reading aloud on a visual exploration task for letters, and that the motivational difference was considered to underlie the difference of performances. The aim of this presentation is to report the performances of a neglect patient having a lesion involving right anterior cingulate gyrus, and discuss the role of anterior cingulate gyrus, towhich the motivational role has been hypothesized. Patient: This 76-year-old woman suffered a subarachnoid hemorrhage seven months previously. After an operation to the anterior communicating artery aneurysm, she had left hemiparesis, and remained in abulic state of mute and motionless until the bromocriptin treatment was started five months later. As her abulia improved gradually, left hemispatial neglect appeared. Method: We prepared a visual exploration task with 44 hiragana letters in apparently random distribution among 44 alphabet foils and presented in front of the midline of t~e patient's body. We requested the patient to read aloud or to cancel all the hiragana letters only. These procedures were carried out in a order of reading - canceling - canceling reading. Then we compared the total number of the errors caused by hemispatial neglect in each response manner. Result: She neglected 19 targets in reading procedure, while the neglect was significantly improved to 2 targets in manual canceling (P
253