TITLE:
Spatial Memory Deficits and Their Correlations with Clusters of Shrunken Neuronal Soma in the Cortices and Limbic System Following a “Mild’’ Mechanical Impact to the Dorsal Skull in Female Rats
AUTHORS:
Wudu E. Lado, Michael A. Persinger
KEYWORDS:
TBI
JOURNAL NAME:
Journal of Behavioral and Brain Science,
Vol.2 No.3,
August
31,
2012
ABSTRACT: Background: Previous results showed that quantitative changes in behavioural accuracies by rats that sustained a “mild” closed head injury were moderately correlated with the total areas (numbers) of anomalous neuronal soma within regions below the impact. Method: Water maze behavioural measures within one day or two months after a single impact of mechanical force over the right dorsal skull, with or without stunning and with or without subsequent pregnancy, were measured and compared to proportions of anomalous neurons under the impact site. Results: The consequences of the impact accommodated about 20% of the variance in the rats’ scores for less proficient spatial learning and memory. There were significantly more anomalous cells within right hemisphere below the impact site that were correlated with poorer initial maze learning. Maternal experience reduced the numbers of anomalous cells in the right limbic area only. Conclusion: These results suggest weak mechanical impacts produce changes in histomorphology within some neurons that are still evident two months later and that the presence of these anomalous clusters, corresponding to less than 1% of the cross-sectional area and below the resolution of contemporary MRI in human cases, are strongly correlated with specific behavioural impairments.