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

The ‘when’ and the ‘where’ of single‐trial allocentric spatial memory performance in young children: Insights into the development of episodic memory

Ribordy Lambert, Farfalla ; Lavenex, Pierre ; Lavenex, Pamela Banta

In: Developmental Psychobiology, 2017, vol. 59, no. 2, p. 185–196

Allocentric spatial memory, “where” with respect to the surrounding environment, is one of the three fundamental components of episodic memory: what, where, when. Whereas basic allocentric spatial memory abilities are reliably observed in children after 2 years of age, coinciding with the offset of infantile amnesia, the resolution of allocentric spatial memory acquired over repeated...

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

Improvement of allocentric spatial memory resolution in children from 2 to 4 years of age

Ribordy Lambert, Farfalla ; Lavenex, Pierre ; Lavenex, Pamela Banta

In: International Journal of Behavioral Development, 2015, vol. 39, no. 4, p. 318–331

Allocentric spatial memory, the memory for locations coded in relation to objects comprising our environment, is a fundamental component of episodic memory and is dependent on the integrity of the hippocampal formation in adulthood. Previous research from different laboratories reported that basic allocentric spatial memory abilities are reliably observed in children after 2 years of age. Based...

Université de Fribourg

No association between ApoE polymorphism and febrile seizures

Lavenex, Pierre ; Lavenex, Pamela Banta ; Cachat, François ; Gehri, Mario ; Juvet, Typhaine

In: Neurological Sciences, 2015, p. 1–6

Seizures associated with fever are a common pediatric problem, affecting about 2–7 % of children between 3 months and 5 years of age. Differentiation of febrile seizures from acute symptomatic seizures secondary to central nervous system infections or seizures associated with fever in children with epilepsy is essential to provide appropriate treatment and follow-up care. Here, we tested the...

Université de Fribourg

Human short-term spatial memory: Precision predicts capacity

Lavenex, Pamela Banta ; Boujon, , Valérie ; Ndarugendamwo, Angélique ; Lavenex, Pierre

In: Cognitive Psychology, 2015, vol. 77, p. 1–19

Here, we aimed to determine the capacity of human short-term memory for allocentric spatial information in a real-world setting. Young adults were tested on their ability to learn, on a trial-unique basis, and remember over a 1-min interval the location(s) of 1, 3, 5, or 7 illuminating pads, among 23 pads distributed in a 4 m × 4 m arena surrounded by curtains on three sides. Participants had to...

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

Development of allocentric spatial memory abilities in children from 18 months to 5 years of age

Ribordy, Farfalla ; Jabès, Adeline ; Banta Lavenex, Pamela A. ; Lavenex, Pierre

In: Cognitive Psychology, 2013, vol. 66, no. 1, p. 1–29

Episodic memories for autobiographical events that happen in unique spatiotemporal contexts are central to defining who we are. Yet, before 2 years of age, children are unable to form or store episodic memories for recall later in life, a phenomenon known as infantile amnesia. Here, we studied the development of allocentric spatial memory, a fundamental component of episodic memory, in two...

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...