ABSTRACT
PURPOSE: To search for metabolic correlates of clinical and electrophysiological abnormalities in violent subjects. METHODS: Seven subjects with histories of extremely violent behavior were studied with positron emission tomography (PET) with fludeoxyglucose F 18 (FDG), brain electrical area mapping, MR imaging, neuropsychiatric and neuropsychological testing, and clinical examination during medical evaluation associated with legal proceedings. Nine control subjects without evidence of organic brain disease were also studied with FDG-PET. Quantitative PET data were calculated as standardized uptake values comparing the highest occipital region with the lowest temporal region. RESULTS: Temporal lobe metabolism was decreased in the study group relative to the control subjects. Medial temporal lobe metabolism was 39% lower than that in the occipital cortex in study subjects and only 27% lower than that in control subjects. These groups differed by Mann-Whitney U test and Wilcoxon's two-sample test. Metabolic differences correlated with limbic neuropsychiatric and electrophysiological abnormalities in the violent group. CONCLUSION: In this selected population of violent subjects, FDG-PET scans showed metabolic abnormalities in the temporal lobes. These abnormalities correlated with limbic abnormalities seen at electrophysiological and neuropsychiatric evaluation.
Subject(s)
Neurocognitive Disorders/diagnosis , Temporal Lobe/metabolism , Tomography, Emission-Computed , Violence , Adolescent , Adult , Biological Psychiatry , Brain Diseases/diagnosis , Brain Diseases/physiopathology , Deoxyglucose/analogs & derivatives , Electroencephalography , Female , Fluorine Radioisotopes , Fluorodeoxyglucose F18 , Forensic Psychiatry , Hippocampus/physiopathology , Humans , Limbic System/physiopathology , Magnetic Resonance Imaging , Male , Memory Disorders/diagnosis , Neurocognitive Disorders/metabolism , Neurocognitive Disorders/physiopathology , Neurocognitive Disorders/psychology , Neuropsychological Tests , Occipital Lobe/diagnostic imaging , Occipital Lobe/metabolism , Radiopharmaceuticals , Temporal Lobe/diagnostic imaging , Violence/psychologyABSTRACT
Using the rapid Golgi method, the morphology of dendritic spines was quantified in the calyxes of groups of newly emerged, nurse, and forager honeybees. These groups were studied because they represented distinct stages of behavioral development and cumulative experience which, according to recent vertebrate findings, may be associated with enlargement of the spine head and stem shortening. Measurements were made of spine density, overall spine length, stem length, maximum head width, and profile area using eyepiece micrometry and computer image analyses. The results indicated that none of the groups differed appreciably in spine density and overall spine length. Foragers did exhibit spines with markedly larger profile areas and shorter stems than those in newly emerged and nurse honeybees. However, nurses and foragers did not differ appreciably in spine head width, but both groups had markedly wider heads than the newly emerged group did. These findings suggest that elongated growth of the spine head and concomitant stem shortening is an incremental process affecting different portions of the spine population at different rates. In particular, the growth rate of most spines appears to accelerate during the foraging stage in which the diversity of sensory stimulation is greatest.
Subject(s)
Bees/anatomy & histology , Behavior, Animal/physiology , Dendrites/ultrastructure , Interneurons/ultrastructure , Visual Cortex/anatomy & histology , Animals , Social EnvironmentABSTRACT
African jewel fish reared with eyeless cave fish, but without visual-tactile contact with conspecifics, exhibit hyperresponsive behavior after release in community aquaria. Because the optic tectum might be affected by these restraints on visual experience, unreleased members of the same social isolate group were compared histologically with controls reared in community aquaria. Using the rapid Golgi method, we counted dendritic spines and branches on pyriform interneurons between 402 and 529 days of age. As compared with isolates, control group interneurons exhibited significantly more spines and primary branches on apical dendrites in deep tectal layers. Our focus is the relation between experiential differences in rearing conditions and synaptic changes in the deep tectal layers.
Subject(s)
Sensory Deprivation , Social Isolation , Superior Colliculi/growth & development , Vision, Ocular , Animals , Dendrites , Interneurons/cytology , Superior Colliculi/cytology , Touch/physiology , Visual Perception/physiologyABSTRACT
Spined pyriform interneurons in community-reared jewel fish have more dendritic branches and spines in the deep tectal layers than those in isolates reared without visual-tactile contact with conspecifics. Furthermore, in the same dendritic loci in which the community-reared fish had more spines, the spine stems were shorter. The findings suggest that social stimulation induces localized formation of spines, which swell with synaptic activation. Shortening of the spine stem through elongated swelling of the spine head is likely to alter synaptic effectiveness through changes in electrotonic conductance.
