Perirhinal cortex

Wiig KA, Bilkey DK. Lesions of rat perirhinal cortex exacerbate the memory deficit observed following damage to the fimbria-fornix. Behav Neurosci 1995 109 620-630. 

Ennaceur A, Neave N, Aggleton JP. Neurotoxic lesions of the perirhinal cortex do not mimic the behavioural effects of fornix transection in the rat. Behav Brain Res... 

Finally, the hippocampus is not the only brain region that is smaller in schizophrenia (Honea et al., 2005 Steen et al., 2006 Velakoulis et al., 2006 Vita et al., 2006). Especially those brain regions that are closely connected with the hippocampus (i.e., amygdala, ERC, perirhinal cortex (PRC), and parahippocampal cortex (PHC)) appear to be affected similarly in schizophrenia (Wright et al., 2000 Sim et al., 2006) ( Figure 3.1-1). 

In the hippocampus, D2 receptor binding is present in the stratum lacunosum molecolare and all layers of subiculum (Mansour et al., 1990 Levey et al., 1993 Yokoyama et al., 1994). In the presubiculum D2 receptor is expressed in layer II, whereas the parasubiculum does not contain D2 receptor. Lower levels of D2 receptor are present in the CA1 field, and in the piriform, entorhinal and perirhinal cortices. In the entorhinal cortex, layers I and III exhibit the highest density of D2 receptor, whereas in the perirhinal cortex a trilaminar pattern of D2 receptor is observed, with the highest levels in the external and deep laminae (Goldsmith and Joyce, 1994). 

In the human hippocampus, the highest binding was found in the molecular layer of the dentate gyrus and subiculum, whereas the binding was lower in CA3 and CA1, and no binding was found in the entorhinal cortex a trilaminar pattern of D2 receptor was instead observed in the perirhinal cortex (Goldsmith and Joyce, 1994). 

As emphasized by Cajal (1911) and later corroborated by Lor-ente de No (1934), the main input to the dentate gyrus is from the entorhinal cortex (but also perirhinal cortex, among others) by way of a fiber system called the perforant path. It is the major input to the hippocampus. The axons of the perforant path arise principally in layers II and III of the entorhinal cortex, with minor contributions from the deeper layers IV and V. Axons... 

Kosel KC, Van Hoesen GW, Rosene DL (1983) A direct projection from the perirhinal cortex (area 35) to the subiculum in the rat. Brain Res 269 347-351. 

The atlas of chemical markers (Paxinos etal., in press [a,b]) enabled us to make a decision on the strengths of the two schemes. On this basis we have retained many of the features of the sensory, motor, and insular areas proposed by Zilles (1985). However, we have curtailed the rostral spread of Zilles s occipital areas and delineated the sensory representation of the trunk region and parietal association area in line with Swanson (1992). We have retained the perirhinal cortex at caudal levels (along with Zilles, 1985) because there is a characteristic NADPH-diaphorase reactivity associated with this area. However, we have delineated the ectorhinal cortex and temporal association area in accordance with Swanson (1992). 

Fig. 16. The developmental expression of GluR-C flop in the rat hippocampus during the first two postnatal weeks (X-ray film, horizontal sections). Arrowheads indicate examples of labelled cells. Hi, hippocampus Ctx, cortex DG, dentate granule cells Ent, entorhinal cortex S, subiculum PRh, perirhinal cortex. Scale bar, 0.8 mm (Monyer et al., 1991 Wisden, Seeburg and Monyer, unpublished).

Tortorella A, Halonen T, Sahibzada N et al (1997) A crucial role of the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid subtype of glutamate receptors in piriform and perirhinal cortex for the initiation and propagation of limbic motor seizures. J Pharmacol Exp Ther 280 1401-1405... 

Gale and colleagues (Halonen et al. 1994) have recently identified key relay sites involved in the spread of seizures triggered in deep prepyriform cortex to other forebrain structures. These studies found that microinjections of muscimol or non-NMDA receptor antagonists into posterior PC or the dorsally adjacent perirhinal cortex prevented the propagation of seizures from rostral PC. 

Halonen, T., Tortorella, A., Zrebect, H. and Gale, K. (1994) Posterior piriform and perirhinal cortex relay seizures evoked from the area tempestas role of excitatory and inhibitory amino acid receptors. Brain Res., 652, 145-148,... 

Perirhinal cortex reduced by 40% full recovery full recovery... 

Salmenpera, T., Kalviainen, R., Partanen, K., Mervaala, E., and Pitkanen, A. 2000. MRl volumetry of the hippocampus, amygdala, entorhinal cortex, and perirhinal cortex after status epilep-ticus. Epilepsy Res 40(2-3) 155-170... 

Myhrer, T., Enger, S., Aas, R, 2010b. Modulators of metabotropic glutamate receptors microinfused into perirhinal cortex anticonvulsant effects in rats challenged with soman. Eur. J. Pharmacol. 636, 82-87. 

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