Structural and functional cerebral changes in patients with schizophrenia and genetic risk-allele carriers

Schizophrenia is one of the most frequent psychiatric disorders and
is associated with a substantial part of worldwide disease burdon1.
The clinical symptoms of patients with schizophrenia can be
separated into positive symptoms such as halluciations and
delusions as well as negative symptoms such as cognitive
impairments, apathy, blunted affect and social withdrawal2. It has
been suggested that understanding the underlying pathophysiological
processes that give rise to these symptoms is a crucial step for
the development of efficient treatment for schizophrenia3. In the
presented work two aspects of the clinical symptomatology of
schizophrenia are analyzed with respect to their potential
neurobiological correlate. Following the dopamine-hypothesis,
patients with schizophrenia exhibit an increase in dopaminergic
neurotransmission in the striatum which might be related to the
experience of positive symptoms4,5. In the first publication
evidence for this dopamine-hypothesis from in-vivo neuroimaging
studies was investigated in a comprehensive meta-analysis. Results
are in the line with the dopamine-hypothesis and point to an
increase of striatal presynaptic dopamine synthesis in
schizophrenia: - Howes OD*, Kambeitz J*, Kim E, Stahl D, Slifstein
M, Abi-Dargham A*, Kapur S* (2012): The nature of dopamine
dysfunction in schizophrenia and what this means for treatment.
Arch Gen Psychiatry 69: 776–786. * these authors contributed
equally ISI Web of Knowledge: Archives of General Psychiatry (now:
JAMA Psychiatry) impact factor 2012: 13.77 5-year impact factor
2012: 14.47 Ranked 3rd of all psychiatry journals The negative
symptoms of schizophrenia such as cognitive impairments have
frequently been associated with changes of cerebral gray matter in
numerous brain regions including the hippocampus6–9. In the second
publication, effects of a potential risk-gene on the hippocampus
are analyzed. Results indicate reduced hippocampal structure and
function in carriers of the met-allele of the BDNF polymorphism
val(66)met: - Kambeitz JP*, Bhattacharyya S*, Kambeitz-Ilankovic
LM, Valli I, Collier DA, McGuire P (2012): Effect of BDNF
val(66)met polymorphism on declarative memory and its neural
substrate: a meta-analysis. Neurosci Biobehav Rev 36: 2165–2177. *
these authors contributed equally ISI Web of Knowledge:
Neuroscience and Biobehavioral Reviews impact factor 2012: 9.44
5-year impact factor 2012: 9.92 Ranked 12th of all neurosciences
journals