The role of medial prefrontal cortex projections to locus ceruleus in mediating the sex differences in behavior in mice with inflammatory pain.

We tested the hypothesis that the cognitive impairment associated with inflammatory pain may result from dysregulation of the top-down control of locus ceruleus's (LC) activity by the medial prefrontal cortex (mPFC). Injection of complete Freund's adjuvant (CFA) served as a model for inflammatory pain. The CFA injection decreased the thermal thresholds in both sexes but only the male mice showed increased anxiety-like behavior and diminished cognition, while the females were not affected. Increased calcium fluorescence, a marker for neuronal activity, was detected by photometry in the mPFC of males but not in females with CFA. Next, while chemogenetic inhibition of the projections from the mPFC to the LC improved the object recognition memory of males with pain, the inhibition of the mPFC to LC pathway in female mice produced anxiolysis and spatial memory deficits. The behavior results prompted us to compare the reciprocal innervation of mPFC and LC between the sexes. We used an anterograde transsynaptic tagging technique, which relies on postsynaptic cre transfer, to assess the innervation of LC by mPFC efferents. The males showed a higher rate of postsynaptic cre transfer into LC neurons from mPFC efferents than the females. And vice versa, a retrograde tracing experiment demonstrated that LC to mPFC projection neurons were more numerous in females when compared to males. In conclusion, we provide evidence that subtle differences in the reciprocal neuronal circuit between the LC and mPFC may contribute to sex differences associated with the adverse cognitive effects of inflammatory pain.

Consumo urbano de yajé (ayahuasca) en Colombia / Urban use of yajé (ayahuasca) in Colombia

El yajé es una sustancia alucinógena, que ha sido usada desde tiempos inmemoriales en las comunidades indígenas de Sur América con fines místicos, adivinatorios y religiosos. En la actualidad, esta sustancia empieza a salir de los contextos indígenas y se filtra en el contexto urbano, en donde su consumo se reviste de un significado y características propias. En el presente estudio se analizan las motivaciones asociadas al consumo de yajé en el contexto urbano. Para tal fin se diseñó una escala de evaluación de motivaciones, la cual fue validada por jueces y aplicada a 40 personas de la ciudad de Bogotá (Colombia) que han consumido el yajé en dos o más ocasiones. También se realizaron entrevistas semiestructuradas a cuatro de los sujetos participantes, con el fin de complementar y enriquecer la información obtenida por la escala.Se encontró que en este grupo de personas las principales motivaciones que impulsan a que el consumo de yajé se repita son las de tipo terapéutico a nivel emocional, en donde el sujeto espera obtener tras el consumo bienestar psíquico, caracterizado por sentimientos de tranquilidad, paz interior, y claridad mental, así como resolver el estancamiento y encontrar soluciones y alternativas de manejo a situaciones personales (AU)

Yajé, a hallucinogenic substance, has been employed for centuries by the indigenous populations of South America, within a mystic and religious context. Recently, the use of yajé has spread from indigenous communities and permeated urban areas, acquiring a different meaning and special characteristics. The motivations for using yajé within an urban context are explored in this study. To this end, a scale was created to measure these motivations, which was validated by experts, and applied to 40 people in Bogotá (Colombia) who had taken yajé on two or more occasions. In addition, there were semistructured interviews of four of the individuals taking part, with the objective of complementing and broadening the information obtained from the scale It was found that the primary motivations in this group for the repeated use of yajé were those of a therapeutic kind at an emotional level, where the subject hopes by taking yajé to reach psychic well-being, characterised by feelings of tranquillity, inner peace and mental clarity, in addition to the ability to resolve personal problems and find alternatives to dealing with personal situations (AU)