Hippocampus imaging

A SPECT imaging study of mescaline showed a hyperfrontal pattern in cerebral blood flow, with greater increases on the right side (Hermie et al. 1992). Increases are also seen in inferior temporal cortex and the hippocampus. Decreases in cerebral blood flow occur in occipital and parietal cortical regions. 

Hall J, Thomas KL, Everitt BJ (2001a) Cellular imaging of zif268 expression in the hippocampus and amygdala during contextual and cued fear memory retrieval selective activation of hippocampal CAl neurons during the recall of contextual memories. J Neurosci 21 2186-2193... 

Morphometric magnetic resonance imaging (MRI) studies provide further support for the concept of a subtle developmental brain anomaly. Szeszko et al. (1999) noted that OCD patients had reduced orbito-frontal and amygdala volumes bilaterally, and absence of the normal hemispheric asymmetry of the hippocampus-amygdala complex. Morphometric measurements of the basal ganglia also reveal decreased caudate size (Robinson et al., 1995 Jenike et al., 1996). 

Figure 2.2 Fear elicits both physical and emotional changes that are coordinated by the amygdala. When a person sees a fear-inducing stimulus (the spider), the image reaches the thalamus, which is relayed to the cortex and hippocampus and projected to the lateral nucleus of the am dala. Once the information reaches the amygdala s central nucleus, the thalamus, hippocampus, and cortex each produce a different fear response.

Over 30 structural imaging studies suggest that major depression is associated with a 5-10% loss of volume in the hippocampus, although some studies have not replicated this finding. Depression and chronic stress states have also been associated with a substantial loss of volume in the anterior cingulate and medial orbital frontal cortex. Loss of volume in structures such as the hippocampus also appears to increase as a function of the duration of illness and the amount of time that the depression remains untreated. 

LA-ICP-MS enables images to be produced of the distribution of essential elements such as Zn, Cu, Fe, S, P, Se and Mn as well as of toxic and also radioactive metals (e.g., Hg, Pb, Cd, Th and U) in thin tissue sections with a spatial resolution in the (im range. This spatial resolution of element distribution analysis is sufficient to distinguish between several layered structures in human brain tissue from the hippocampus, as described by Zilles et al.162... 

---