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S A Bachneff

Publications and source records attributed to S A Bachneff.

4 recordsLinked to original sources
PubMed1996

Regional cerebral blood flow in schizophrenia and the local circuit neurons hypothesis.

It has been suggested that nitric oxide, a nonconventional intra- and intercellular messenger involved in various biological and nervous system functions, may play a crucial role in a sophisticated cerebral microvascular system that regulates cerebral blood flow (CBF) under resting and activated conditions. A review of regional cerebral blood flow (rCBF) studies is schizophrenia shows that in schizophrenia patients this microvascular regulatory system may be deficient, failing to selectively raise rCBF in areas of the frontal and temporal lobes to respond to the physiological load placed on brain cells in these areas during certain neuropsychological tasks. A hypothesis about the more general role of local circuit neurons (LCNs) in the pathophysiology of schizophrenia is revised in light of recent information about both the characterization of LCN subpopulations and the interactions of multiple neuro-transmitter systems in midbrain, striatum, and cortex. This revision helps explain the subtle rCBF regulatory failure, as well as other failures in information processing, in schizophrenia patients and points to interneurons as likely sites for the action of both typical and atypical antipsychotic drugs.

Brain↗
PubMed1991

Positron emission tomography and magnetic resonance imaging: a review and a local circuit neurons hypo(dys)function hypothesis of schizophrenia.

A review of brain imaging (PET and MRI) studies on schizophrenia and recent data from neuroanatomy, neurophysiology, neuropathology, neurochemistry, neuropsychology, and cortical organization theory is integrated with the concept of local circuit neurons (LCNs) in a new hypothesis--the local circuit neurons hypo(dys)function hypothesis of schizophrenia--that attempts to explain the pathogenesis and pathophysiology of schizophrenia through a hypofunction (or dysfunction) of the local circuit neurons in prefrontal and limbic-temporal areas. This hypofunction (dysfunction) is then related to the neurocircuitry, neuropsychology, and psychopathology of schizophrenia.

Brain↗
PubMed1983

Correlates of cerebral event-related slow potentials and psychopathology.

The study explored associations between the cerebral event-related slow potentials (ERSP) and psychiatric symptoms and syndromes as reflected by the Present State Examination (PSE) in 36 randomly selected psychiatric in-patients. Independent raters measured the readiness potential (RP), contingent negative variation (CNV) and post-imperative negative variation (PINV) in terms of their amplitude and duration. The 360 individual PSE items were grouped into units of analysis (UA) and further collapsed into groups of units of analysis (GUA). Canonical correlations were computed between two sets of variables (psychological and electrophysiological). Kendall's rank-order correlation was used as the main statistical approach. Some psychotic signs were associated with increased PINV amplitude. Obsessive thoughts, ideas of reference and verbal hallucinations correlated with longer PINV duration. Hopelessness and suicidal thoughts (affect-laden thoughts) as well as first-rank Schneiderian symptoms (FRS) were negatively correlated with CNV amplitude. The results support the hypothesis that CNV and PINV, alone or in combination, can be used to indicate the presence or absence of identifiable psychiatric symptoms and syndromes. The implications of electrophysiological correlates of psychopathology for psychiatric nosology and for the validity of psychiatric symptoms and syndromes were discussed.

Adolescent↗