Group-wise 3D registration based templates to study the evolution of ant worker neuroanatomy

The evolutionary success of ants and other social insects is considered to be intrinsically linked to division of labor and emergent collective intelligence. The role of the brains of individual ants in generating these processes, however, is poorly understood. One genus of ant of special interest is Pheidole, which includes more than a thousand species, most of which are dimorphic, i.e. their colonies contain two subcastes of workers: minors and majors. Using confocal imaging and manual annotations, it has been demonstrated that minor and major workers of different ages of three species of Pheidole have distinct patterns of brain size and subregion scaling. However, these studies require laborious effort to quantify brain region volumes and are subject to potential bias. To address these issues, we propose a group-wise 3D registration approach to build for the first time bias-free brain atlases of intra- and inter-subcaste individuals and automatize the segmentation of new individuals.Comment: 10 pages, 5 figures, preprint for conference (not reviewed

Flexibility of neuronal codes:adaptation to stimulus statistics in a mechanosensorial neuron firing in bursts

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Anatomía, Histología y Neurociencia

Single neuron activity-dependent signal processing

Activity in a neural network can affect both the synaptic strengths and the intrinsic electrical properties of neurons within the network. Changes of the intrinsic properties can enhance, reduce or stabilize the neural excitability. One of the activity-dependent regulatory mechanisms is the afterhyperpolarization, generally due to the activation of K+ conductances and to a Na+/K+ pump. In many neurons, the afterhyperpolarization is modified after a period of spike activity. In the mechanosensory T neurons of the leech, a prolonged electrical activity produces an increase of the afterhyperpolarization. This is believed to induce conduction block of spikes in several regions of the neuron, which in turn may decrease presynaptic invasion of spikes and thereby decrease transmitter release. To explore this possibility, we developed a multicompartment model of a T neuron [1]. The model incorporated empirical data describing the geometry of the cell and activity-dependent changes of the afterhyperpolarization. Simulations indicated that at some branching points activity-dependent increases of the afterhyperpolarization reduced the number of spikes transmitted from the receptive fields to the soma and beyond. Simulations also showed that the afterhyperpolarization could modulate transmission from the soma to the synaptic terminals, suggesting that it can regulate spike conduction within the presynaptic arborizations of the neuron, contributing to the synaptic depression correlated with increases in the afterhyperpolarization. In order to investigate how the afterhyperpolarization modulatory capabilities on transmission were dependent on the axonal geometry as well as on membrane properties, we developed [2] another multicompartment model of the mechanosensory cell, representing the reduced version of the model developed in [1]. The simulations suggested that channel kinetics influence the afterhyperpolarization-dependent modulation of spike conduction through points of impedance mismatch. The processing or conductive features of neurons seems to be determined in the first instance by the channel kinetics of the membrane and secondarily by the axonal geometry and activity-dependent processes and noise. We have also showed [3] that the role of the afterhyperpolarization induced by Na+/K+ pump-activity, which consists in a slow reduction in excitability, is also involved in neuronal coding. We showed that the regulation of excitability by Na+/K+ pump-activity is necessary for the neuron to make different responses depending on the statistical context of the stimuli. We investigate the role of membrane kinetics and input conductance mismatch in the adaptation of spike bursting to stimulus statistics

Método de transformación de imágenes en nubes de puntos de espacios multidimensionales, método de identificación de objetos e individuos, método de segmentación, método de localización de puntos de interés y usos

Método de transformación de imágenes en espacios multidimensionales que selecciona combinaciones de pixeles de imágenes, calcula para cada combinación de pixeles una distancia entre cada par de pixeles y una intensidad de cada píxel y genera una nube de puntos en espacios multidimensionales, mediante una asignación, a cada combinación de pixeles, de un punto en los espacios multidimensionales cuyas coordenadas corresponden con unos valores seleccionados entre las distancias, intensidades y una combinación. Además se describe un método de identificación de objetos e individuos, un método de segmentación, un método de localización de puntos de interés y usos de los mismos basados todos ellos en el método de transformaciónPeer reviewedConsejo Superior de Investigaciones CientíficasA1 Solicitud de patente con informe sobre el estado de la técnic

Método de transformación de imágenes en nubes de puntos de espacios multidimensionales, método de identificación de objetos e individuos, método de segmentación, método de localización de puntos de interés y usos

Método de transformación de imágenes en espacios multidimensionales que selecciona combinaciones de pixeles de imágenes, calcula para cada combinación de pixeles una distancia entre cada par de pixeles y una intensidad de cada píxel y genera una nube de puntos en espacios multidimensionales, mediante una asignación, a cada combinación de pixeles, de un punto en los espacios multidimensionales cuyas coordenadas corresponden con unos valores seleccionados entre las distancias, intensidades y una combinación. Además se describe un método de identificación de objetos e individuos, un método de segmentación, un método de localización de puntos de interés y usos de los mismos basados todos ellos en el método de transformaciónPeer reviewedConsejo Superior de Investigaciones CientíficasB1 Patente sin examen previ

Correction: Division of labor and brain evolution in insect societies: Neurobiology of extreme specialization in the turtle ant Cephalotes varians.

[This corrects the article DOI: 10.1371/journal.pone.0213618.]

Origins of Aminergic Regulation of Behavior in Complex Insect Social Systems

Neuromodulators are conserved across insect taxa, but how biogenic amines and their receptors in ancestral solitary forms have been co-opted to control behaviors in derived socially complex species is largely unknown. Here we explore patterns associated with the functions of octopamine (OA), serotonin (5-HT) and dopamine (DA) in solitary ancestral insects and their derived functions in eusocial ants, bees, wasps and termites. Synthesizing current findings that reveal potential ancestral roles of monoamines in insects, we identify physiological processes and conserved behaviors under aminergic control, consider how biogenic amines may have evolved to modulate complex social behavior, and present focal research areas that warrant further study

Editorial: Neuroethology of the colonial mind: Ecological and evolutionary context of social brains

International audienceCollective behavior relies on interactions among individuals who have neural substrates supporting the exchange and processing of social information (Gordon, 2021). The collective acquisition and processing of information in these advanced societies suggest that individuals form a "colonial mind." Over the past decades, studies of individual and collective cognition have received a lot of attention (Couzin, 2009; Simons and Tibbetts, 2019). However, little is known about how the two systems interact: individual cognitive abilities are not correlated to collective cognitive abilities (Feinerman and Korman, 2017). Addressing this question requires a better understanding of the mechanisms of both individual and collective cognition. For this Research Topic, we brought together researchers in neuroscience and collective animal behavior to further examine the colonial mind. It is now clear that collective behavior can yield fitness benefits to animals (Krause et al., 2010). For instance, grouped animals often respond faster and more accurately to changes in environmental or social circumstances than isolated conspecifics (Sumpter, 2010). Through the genetic control of Drosophila behavior, Ferreira et al. showed how social information influences individual reactions in threatening situations. This study indicates that collective cognition can benefit individuals across the animal kingdom, even in loosely social species. By contrast, the mechanisms underlying the transition from solitary to group living are much less understood. Several physiological changes may have contributed to division of labor in highly social species. Sasaki et al. provide a comparative perspective to understand how neurotransmitters and hormones evolved to support eusociality. The authors compiled literature from eusocial and non-social Frontiers in Ecology and Evolution frontiersin.or