Université de Fribourg

Developmental regulation of expression of schizophrenia susceptibility genes in the primate hippocampal formation

Favre, Guillaume ; Banta Lavenex, Pamela A. ; Lavenex, Pierre

In: Translational Psychiatry, 2012, vol. 2, p. e173

The hippocampal formation is essential for normal memory function and is implicated in many neurodevelopmental, neurodegenerative and neuropsychiatric disorders. In particular, abnormalities in hippocampal structure and function have been identified in schizophrenic subjects. Schizophrenia has a strong polygenic component, but the role of numerous susceptibility genes in normal brain development...

Université de Fribourg

Postnatal development of the hippocampal formation: A stereological study in macaque monkeys

Jabès, Adeline ; Banta Lavenex, Pamela A. ; Amaral, 3 David G. ; Lavenex, Pierre

In: The Journal of Comparative Neurology, 2011, p. -

We performed a stereological analysis of neuron number, neuronal soma size, and volume of individual regions and layers of the macaque monkey hippocampal formation during early postnatal development. We found a protracted period of neuron addition in the dentate gyrus throughout the first postnatal year and a concomitant late maturation of the granule cell population and individual dentate gyrus...

Université de Fribourg

Quantitative analysis of postnatal neurogenesis and neuron number in the macaque monkey dentate gyrus

Jabès, Adeline ; Banta Lavenex, Pamela A. ; Amaral, David G. ; Lavenex, Pierre

In: European Journal of Neuroscience, 2010, vol. 31, no. 2, p. 273-285

The dentate gyrus is one of only two regions of the mammalian brain where substantial neurogenesis occurs postnatally. However, detailed quantitative information about the postnatal structural maturation of the primate dentate gyrus is meager. We performed design-based, stereological studies of neuron number and size, and volume of the dentate gyrus layers in rhesus macaque monkeys (Macaca...

Université de Fribourg

Intrinsic connections of the macaque monkey hippocampal formation: II. CA3 connections

Kondo, Hideki ; Lavenex, Pierre ; Amaral, David G.

In: The Journal of Comparative Neurology, 2009, vol. 515, no. 3, p. 349 - 377

We examined the topographic organization of the connections of the CA3 field of the macaque monkey hippocampus. Discrete anterograde and retrograde tracer injections were made at various positions within CA3 and CA1. The projections from CA3 to CA1 (Schaffer collaterals), which terminate in the strata radiatum, pyramidale, and oriens, are present throughout the entire transverse extent of CA1....

Université de Fribourg

Postmortem changes in the neuroanatomical characteristics of the primate brain: Hippocampal formation

Lavenex, Pierre ; Lavenex, Pamela Banta ; Bennett, Jeffrey L. ; Amaral, David G.

In: The Journal of Comparative Neurology, 2009, vol. 512, no. 1, p. 27 - 51

Comparative studies of the structural organization of the brain are fundamental to our understanding of human brain function. However, whereas brains of experimental animals are fixed by perfusion of a fixative through the vasculature, human or ape brains are fixed by immersion after varying postmortem intervals. Although differential treatments might affect the fundamental characteristics of the...

Université de Fribourg

Intrinsic connections of the macaque monkey hippocampal formation: I. Dentate gyrus

Kondo, Hideki ; Lavenex, Pierre ; Amaral, David G.

In: The Journal of Comparative Neurology, 2008, vol. 511, no. 4, p. 497 - 520

We have carried out a detailed analysis of the intrinsic connectivity of the Macaca fascicularis monkey hippocampal formation. Here we report findings on the topographical organization of the major connections of the dentate gyrus. Localized anterograde tracer injections were made at various rostrocaudal levels of the dentate gyrus, and we investigated the three-dimensional organization of the...

Université de Fribourg

Hippocampal lesion prevents spatial relational learning in adult Macaque monkeys

Lavenex, Pamela Banta ; Amaral, David G. ; Lavenex, Pierre

In: The Journal of Neuroscience, 2006, vol. 26(17), p. 4546-4558

The role of the hippocampus in spatial learning and memory has been extensively studied in rodents. Comparable studies in nonhuman primates, however, are few, and findings are often contradictory. This may be attributable to the failure to distinguish between allocentric and egocentric spatial representations in experimental designs. For this experiment, six adult monkeys received bilateral...