14 research outputs found
Global reward state affects learning and activity in raphe nucleus and anterior insula in monkeys
202009 bcrcVersion of RecordPublishe
Differential investment in visual and olfactory brain areas reflects behavioural choices in hawk moths
Differences in reward processing between putative cell types in primate prefrontal cortex
Variability in visual cortex size reflects tradeoff between local orientation sensitivity and global orientation modulation
Inverted activity patterns in ventromedial prefrontal cortex during value-guided decision-making in a less-is-more task
Evo-Devo and Brain Scaling: Candidate Developmental Mechanisms for Variation and Constancy in Vertebrate Brain Evolution
Comparison of Area 17 Cellular Composition in Laboratory and Wild-Caught Rats Including Diurnal and Nocturnal Species
In this study we examine the size of primary sensory areas in the neocortex and the cellular composition of area 17/V1 in three rodent groups: laboratory nocturnal Norway rats (Long-Evans; Rattus norvegicus), wild-caught nocturnal Norway rats (R. norvegicus), and laboratory diurnal Nile grass rats (Arvicanthis niloticus). Specifically, we used areal measures of myeloarchitecture of the primary sensory areas to compare area size and the isotropic fractionator method to estimate the number of neurons and nonneurons in area 17 in each species. Our results demonstrate that the percentage of cortex devoted to area 17 is significantly greater and the percentage of cortex devoted to S1 is significantly smaller in the diurnal Nile grass rat compared with the nocturnal Norway rat groups. Further, the laboratory rodent groups have a greater percentage of cortex devoted to auditory cortex compared with the wild-caught group. We also demonstrate that wild-caught rats have a greater density of neurons in area 17 compared to laboratory-reared animals. However, there were no other clear cellular composition differences in area 17 or differences in the percentage of brain weight devoted to area 17 between nocturnal and diurnal rats. Thus, there are differences in primary sensory area size between diurnal versus nocturnal and laboratory versus wild-caught rat groups and cellular density between wild-caught and laboratory rat groups. Our results demonstrate that the differences in the size and cellular composition of cortical areas do not fit with what would be expected based on brain scaling differences alone, and have a consistent relationship with lifestyle and sensory morphology