Université de Fribourg

Postnatal development of the entorhinal cortex: a stereological study in macaque monkeys

Piguet, Olivia ; Chareyron, Loïc J. ; Banta Lavenex, Pamela ; Amaral, David G. ; Lavenex, Pierre

In: Journal of Comparative Neurology, 2020, vol. 528, no. 14, p. 2308-2332

The entorhinal cortex is the main gateway for interactions between the neocortex and the hippocampus. Distinct regions, layers, and cells of the hippocampal formation exhibit different profiles of structural and molecular maturation during postnatal development. Here, we provide estimates of neuron number, neuronal soma size, and volume of the different layers and subdivisions of the monkey...

Université de Fribourg

Stereological analysis of the rhesus monkey entorhinal cortex

Piguet, Olivia ; Chareyron, Loïc J. ; Lavenex, Pamela Banta ; Amaral, David G. ; Lavenex, Pierre

In: Journal of Comparative Neurology, 2018, vol. 526, no. 13, p. 2115–2132

The entorhinal cortex is a prominent structure of the medial temporal lobe, which plays a pivotal role in the interaction between the neocortex and the hippocampal formation in support of declarative and spatial memory functions. We implemented design‐based stereological techniques to provide estimates of neuron numbers, neuronal soma size, and volume of different layers and subdivisions of...

Université de Fribourg

Functional organization of the medial temporal lobe memory system following neonatal hippocampal lesion in rhesus monkeys

Chareyron, Lo?c J. ; Lavenex, Pamela Banta ; Amaral, David G. ; Lavenex, Pierre

In: Brain Structure and Function, 2017, vol. 222, no. 9, p. 3899–3914

Hippocampal damage in adult humans impairs episodic and semantic memory, whereas hippocampal damage early in life impairs episodic memory but leaves semantic learning relatively preserved. We have previously shown a similar behavioral dissociation in nonhuman primates. Hippocampal lesion in adult monkeys prevents allocentric spatial relational learning, whereas spatial learning persists...

Université de Fribourg

Neural reorganization due to neonatal amygdala lesions in the Rhesus monkey: changes in morphology and network structure

Grayson, D. S. ; Bliss-Moreau, E. ; Bennett, J. ; Lavenex, Pierre ; Amaral, David G.

In: Cerebral Cortex, 2017, p. 1–14

It is generally believed that neural damage that occurs early in development is associated with greater adaptive capacity relative to similar damage in an older individual. However, few studies have surveyed whole brain changes following early focal damage. In this report, we employed multimodal magnetic resonance imaging analyses of adult rhesus macaque monkeys who had previously undergone...

Université de Fribourg

Selective lesion of the hippocampus increases the differentiation of immature neurons in the monkey amygdala

Chareyron, Loïc J. ; Amaral, David G. ; Lavenex, and Pierre

In: Proceedings of the National Academy of Sciences, 2016, vol. 113, no. 50, p. 14420–14425

A large population of immature neurons is present in the ventromedial portion of the adult primate amygdala, a region that receives substantial direct projections from the hippocampal formation. Here, we show the effects of neonatal (n = 8) and adult (n = 6) hippocampal lesions on the populations of mature and immature neurons in the paralaminar, lateral, and basal nuclei of the adult monkey...

Université de Fribourg

An analysis of entorhinal cortex projections to the dentate gyrus, hippocampus, and subiculum of the neonatal macaque monkey

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

In: Journal of Comparative Neurology, 2013, p. -

The entorhinal cortex is the primary interface between the hippocampal formation and neocortical sources of sensory information. While much is known about the cells of origin, termination patterns and topography of the entorhinal projections to other fields of the adult hippocampal formation, very little is known about the development of these pathways, particularly in the human or nonhuman...

Université de Fribourg

Postnatal development of the amygdala: A stereological study in macaque monkeys

Chareyron, Loïc J. ; Banta Lavenex, Pamela A. ; Amaral, David G. ; Lavenex, Pierre

In: The Journal of Comparative Neurology, 2012, p. -

Abnormal development of the amygdala has been linked to several neurodevelopmental disorders, including schizophrenia and autism. However, the postnatal development of the amygdala is not easily explored at the cellular level in humans. Here, we performed a stereological analysis of the macaque monkey amygdala in order to characterize the cellular changes underlying its normal structural...

Université de Fribourg

Stereological analysis of the rat and monkey amygdala

Chareyron, Loïc J. ; Banta Lavenex, Pamela A. ; Amaral, David G. ; Lavenex, Pierre

In: The Journal of Comparative Neurology, 2011, vol. 519, no. 16, p. 3218–3239

The amygdala is part of a neural network that contributes to the regulation of emotional behaviors. Rodents, especially rats, are used extensively as model organisms to decipher the functions of specific amygdala nuclei, in particular in relation to fear and emotional learning. Analysis of the role of the nonhuman primate amygdala in these functions has lagged work in the rodent but provides...

Université de Fribourg

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

Jabès, Adeline ; Banta Lavenex, Pamela A. ; Amaral, 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...

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...