Adolescent consumption of sweetened beverages and their motivational effects in adulthood: an animal model

Estudios previos en roedores sugieren que el consumo de azúcares en la adolescencia disminuye el valor de los estímulos palatables en la adultez, llevando a un déficit motivacional. Se presentan dos experimentos en ratas macho en el que se exploran los efectos motivacionales de largo término del consumo adolescente de una solución azucarada al 5%. En comparación con un grupo control, las ratas experimentales pesaron más en la adultez y mostraron un impacto emocional atenuado ante la devaluación y la omisión de un estímulo palatable. El segundo experimento mostró una preferencia menor por una solución de sacarosa al 4% en una prueba de preferencia de 2 horas. El menor impacto emocional ante eventos de frustración y la menor preferencia por la sacarosa son resultados consistentes con la hipótesis de déficit motivacional en la adultez. Esta condición podría ser uno de los mecanismos asociados a la propensión al sobrepeso en adultos.Fil: Ilarraz, Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Serafini, Matías. Instituto de Investigaciones Microbilogicas y Clinicas.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Laurito, Micaela. Instituto de Investigaciones Microbilogicas y Clinicas.; ArgentinaFil: Cuenya, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Investigaciones Microbilogicas y Clinicas.; Argentin

Plasticity of Cortico-striatal Neurons of the Caudal Anterior Cingulate Cortex During Experimental Neuropathic Pain

Maladaptive neuronal plasticity is a main mechanism for the development and maintenance of pathological pain. Affective, motivational and cognitive deficits that are comorbid with pain involve cellular and synaptic modifications in the anterior cingulate cortex (ACC), a major brain mediator of pain perception. Here we use a model of neuropathic pain (NP) in male mice and ex-vivo electrophysiology to investigate whether layer 5 caudal ACC (cACC) neurons projecting to the dorsomedial striatum (DMS), a critical region for motivational regulation of behavior, are involved in aberrant neuronal plasticity. We found that while the intrinsic excitability of cortico-striatal cACC neurons (cACC-CS) was preserved in NP animals, excitatory postsynaptic potentials (EPSP) induced after stimulation of distal inputs were enlarged. The highest synaptic responses were evident both after single stimuli and in each of the EPSP that compose responses to trains of stimuli, and were accompanied by increased synaptically-driven action potentials. EPSP temporal summation was intact in ACC-CS neurons from NP mice, suggesting that the plastic changes were not due to alterations in dendritic integration but rather through synaptic mechanisms. These results demonstrate for the first time that NP affects cACC neurons that project to the DMS and reinforce the notion that maladaptive plasticity of the cortico-striatal pathway may be a key factor in sustaining pathological pain.Fil: Trujillo, María Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Ilarraz, Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Kasanetz, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; Argentin

Increment in the consummatory response induced by reward delay: An animal model of binge-like eating episodes

The omission of an expected palatable reinforcer produces an aversive emotional state, called frustration, that could function as an important factor in the etiology and maintenance of the binge-eating disorder. A series of experiments carried out in adult male Wistar rats are presented, in which the consummatory response of sugary drinks was evaluated after events of frustration due to reward delay. The animals were trained in a consummatory behavior acquisition phase, in which they had access to different concentrations of sucrose solutions. In the test phase, a control group received the reinforcer normally, while an experimental group received it after a delay. A significant increase in the consummatory behavior of a 32 % sucrose was found in the group that was exposed to a 2-min delay before re-introducing the reinforcer (Experiment 1). The increment found in the consummatory response was dependent on the aversive state of frustration. This could be concluded because, in a less frustrating condition, the animals did not exhibit the phenomenon (Experiment 2), and a more frustrating one produced an increment of the effect (Experiment 3). This result was also observed using a direct measure of consumption -kilocalorie intake- during several events of reinforcement delay (Experiment 4).Fil: Serafini, Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Ilarraz, Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Laurito, Micaela. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Cuenya, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; Argentin