Stria medullaris innervation follows the transcriptomic division of the habenula.

The habenula is a complex neuronal population integrated in a pivotal functional position into the vertebrate limbic system. Its main afference is the stria medullaris and its main efference the fasciculus retroflexus. This neuronal complex is composed by two main components, the medial and lateral habenula. Transcriptomic and single cell RNAseq studies have unveiled the morphological complexity of both components. The aim of our work was to analyze the relation between the origin of the axonal fibers and their final distribution in the habenula. We analyzed 754 tracing experiments from Mouse Brain Connectivity Atlas, Allen Brain Map databases, and selected 12 neuronal populations projecting into the habenular territory. Our analysis demonstrated that the projections into the medial habenula discriminate between the different subnuclei and are generally originated in the septal territory. The innervation of the lateral habenula displayed instead a less restricted distribution from preoptic, terminal hypothalamic and peduncular nuclei. Only the lateral oval subnucleus of the lateral habenula presented a specific innervation from the dorsal entopeduncular nucleus. Our results unveiled the necessity of novel sorts of behavioral experiments to dissect the different functions associated with the habenular complex and their correlation with the distinct neuronal populations that generate them.

The ATENción Plena en Enfermedad de Alzheimer (ATENEA-Mindfulness in Alzheimer's Disease) Program for Caregivers: Study Protocol for a Randomized Controlled Trial.

A person affected by Alzheimer's disease (AD) gradually loses the ability to perform activities of daily living and becomes dependent on caregivers, thereby having a negative impact on the caregivers' quality of life. There is evidence that suggests that interventions aimed at caregivers, such as mindfulness, may be effective at reducing this burden and emotional issues, such as depression and anxiety, and improving their quality of life. However, there is a lack of consistency in the findings and conclusions remain tentative. In addition, as neuropsychiatric symptoms (NPSs) of AD are major determinants of the caregiver's burden, these interventions should examine the relationship between these symptoms and caregiver outcomes. Importantly, to improve the design of therapeutic interventions for caregivers and complement the treatment of AD, aspects related to occupational performance and the participation of people with AD and their caregivers should also be considered. Therefore, this study will aim to examine first, the effects of a mindfulness-based program designed for caregivers on NPSs of AD and caregivers' anxiety and depression; second, the effects of this program on patients' functional capacity, cognitive performance, executive functions, and quality of life, and on caregivers' burden, quality of life, occupational balance, executive functions, psychological wellbeing, and self-compassion. We believe that the findings of this study will have significant implications for future healthcare strategies focused on improving the quality of life and wellbeing of caregivers.

Neuronal tangential migration from Nkx2.1-positive hypothalamus.

During the development of the central nervous system, the immature neurons suffer different migration processes. It is well known that Nkx2.1-positive ventricular layer give rise to critical tangential migrations into different regions of the developing forebrain. Our aim was to study this phenomenon in the hypothalamic region. With this purpose, we used a transgenic mouse line that expresses the tdTomato reporter driven by the promotor of Nkx2.1. Analysing the Nkx2.1-positive derivatives at E18.5, we found neural contributions to the prethalamic region, mainly in the zona incerta and in the mes-diencephalic tegmental region. We studied the developing hypothalamus along the embryonic period. From E10.5 we detected that the Nkx2.1 expression domain was narrower than the reporter distribution. Therefore, the Nkx2.1 expression fades in a great number of the early-born neurons from the Nkx2.1-positive territory. At the most caudal positive part, we detected a thin stream of positive neurons migrating caudally into the mes-diencephalic tegmental region using time-lapse experiments on open neural tube explants. Late in development, we found a second migratory stream into the prethalamic territory. All these tangentially migrated neurons developed a gabaergic phenotype. In summary, we have described the contribution of interneurons from the Nkx2.1-positive hypothalamic territory into two different rostrocaudal territories: the mes-diencephalic reticular formation through a caudal tangential migration and the prethalamic zona incerta complex through a dorsocaudal tangential migration.