Area Parahippocampalis

Cell proliferation was examined in the intermediate medial mesopallium (IMM), arcopallium intermedium (AI), medial part of nidopallium and mesopallium (MNM), nidopallium dorso-caudalis (Ndc), hippocampus (Hp) and area parahippocampalis (APH), as well as in corresponding ventricular zones.  

At 24 h post-BrdU injection, there was a significant reduction in labelling in MeA-trained chicks in both the dorsal hippocampus and area parahippocampalis, in comparison to controls.  

Neither discrimination was impaired by damage to the hippocampus and area parahippocampalis.  

We examined the effects of hippocampus (Hp) and area parahippocampalis (APH) lesions in pigeons on their ability to perform a battery of tasks including autoshaping, time discrimination, spatial memory, and pattern discrimination.  

Pigeons (Columba livia) with bilateral electrolytic lesions of the hippocampus and area parahippocampalis were compared with control pigeons on 2 tasks: negative patterning and delayed spatial alternation.  

In the present study we used the retrograde tracer cholera toxin subunit B, the anterograde tracer biotinylated dextran amine, and standard extracellular recording techniques to investigate whether the hippocampal formation [ which consists of the hippocampus proper and the area parahippocampalis (Hp/APH) in pigeons] receives information from the accessory optic system (AOS).  

Two experiments were conducted to examine the effects of bilateral hippocampus (Hp) and area parahippocampalis (APH) lesions in pigeons on the acquisition of a visual and spatial task.  

Four experiments were conducted to determine the effects of bilateral damage to the hippocampus and area parahippocampalis (Hp-APH) on visual memory in pigeons using the delayed matching-to-sample (DMS) procedure.  

Serotonin-IR fibers and terminals were found to be very broadly distributed within the brain and were particularly prominent in several structures of the telencephalon (archistriatum pars dorsalis, nucleus taeniae, area parahippocampalis, septum), diencephalon (nuclei preopticus medianus, magnocellularis, nucleus geniculatus lateralis pars ventralis, nucleus triangularis, nucleus pretectalis), mesencephalon-rhombencephalon (superficial layers of the optic tectum, nucleus ectomamillaris, nucleus isthmo-opticus and in most of the cranial nerve nuclei).  

Finally, HIS/HD have projections predominantly to HA and the dorsocaudal telencephalon (area corticoidea dorsolateralis and area parahippocampalis), as well as relatively minor projections to the areas which also receive projections from HA.  

Distinct populations of labeled cells were also detected in the hyperstriatum accessorium, hippocampus, area parahippocampalis, nucleus of the diagonal band, cortex dorsolateralis, and cortex piriformis. For instance, the bulbus olfactorius was heavily labeled in the pigeon, but was not labeled in the chicken, and numerous PPE mRNA-containing cells were present in the area parahippocampalis of pigeons but not of chickens.  

The distribution of VIP-immunoreactive neurons and fibers was detected in the extrahypothalamic areas of chicken brain by immunohistochemistry and light microscopy VIP-ir perikarya were found in the hippocampus and in the area parahippocampalis; in the area ventralis of Tsai, in the n.  

For the majority of the substances, developmental patterns in the distribution of immunoreactivity differ between the hippocampus proper and the area parahippocampalis, the two major areas that together make up the avian hippocampal complex.  

The highest densities of binding sites were observed in the hyperstriatum dorsale, archistriatum, auditory field L of neostriatum, area corticoidea dorsolateralis and temporo-parieto-occipitalis, area parahippocampalis, tectum opticum, nucleus dorsomedialis anterior thalami, and in the periventricular area of the hypothalamus. Fibers and terminals were observed in the area corticoidea dorsolateralis, area parahippocampalis, hippocampus, hyperstriatum accessorium, hyperstriatum dorsale, archistriatum, tuberculum olfactorium, nuclei dorsolateralis and dorsomedialis of the thalamus, and throughout the hypothalamus and the median eminence.  

There was one striking exception to this rule: no immunoreactivity was detected in the zebra finch telencephalon, while assays had shown the presence of an active enzyme in several nuclei such as the robustus archistriatalis, the hyperstriatum ventrale pars caudale, and the hippocampus and area parahippocampalis.  

High concentrations were also observed in the hippocampus, area parahippocampalis, neostriatum, neostriatum intermedium and hyperstriatum ventrale.  

Intermediate levels were found throughout the paleostriatal regions, septum, thalamus, archistriatum, hyperstriatum accessorium and area parahippocampalis whilst in hippocampus and ectostriatum the density of [ 3H]naloxone binding sites was low.  

It has also been previously shown that the hippocampal complex (hippocampus and area parahippocampalis) plays an important role in memory for cache sites.  

Three experiments examined the behavioural effects of bilateral ablation of the avian hippocampus-area parahippocampalis (Hp-APH), a region which is considered to be the homologue of the mammalian hippocampal formation.  

[ View All ]