The neural circuits of monogamous behavior.

The interest in studying the neural circuits related to mating behavior and mate choice in monogamous species lies in the parallels found between human social structure and sexual behavior and that of other mammals that exhibit social monogamy, potentially expanding our understanding of human neurobiology and its underlying mechanisms. Extensive research has suggested that social monogamy, as opposed to non-monogamy in mammals, is a consequence of the neural encoding of sociosensory information from the sexual partner with an increased reward value. Thus, the reinforced value of the mate outweighs the reward value of mating with any other potential sexual partners. This mechanism reinforces the social relationship of a breeding pair, commonly defined as a pair bond. In addition to accentuated prosocial behaviors toward the partner, other characteristic behaviors may appear, such as territorial and partner guarding, selective aggression toward unfamiliar conspecifics, and biparental care. Concomitantly, social buffering and distress upon partner separation are also observed. The following work intends to overview and compare known neural and functional circuits that are related to mating and sexual behavior in monogamous mammals. We will particularly discuss reports on Cricetid rodents of the Microtus and Peromyscus genus, and New World primates (NWP), such as the Callicebinae subfamily of the titi monkey and the marmoset (Callithrix spp.). In addition, we will mention the main factors that modulate the neural circuits related to social monogamy and how that modulation may reflect phenotypic differences, ultimately creating the widely observed diversity in social behavior.

First case of delayed traumatic intracerebral hemorrhage in a patient with undiagnosed factor XI deficiency: diagnosis and management review.

Factor XI (FXI) deficiency, also known as hemophilia C, is included in the rare bleeding disorders (RBDs). It is distinct from other coagulation factor deficiencies because it rarely presents as spontaneous hemorrhage, but rather as bleeding after trauma or surgery; in addition, the severity of bleeding does not correlate with FXI levels. Most delayed traumatic intracerebral hemorrhage (DTICH) occurs during the first 72 hours of the trauma. Factors that contribute to its formation include local or systemic coagulopathy, among others. Hemorrhagic cases of FXI deficiency related to the central nervous system (CNS) are very rare, with only 13 reported cases. To the best of our knowledge, this is the first reported case of a DTICH in a patient with undiagnosed FXI deficiency.

Radiologic and Histopathologic Features in an Intracranial Localized Castleman Disease: A Case Report and Review of Literature.

INTRODUCTION: Castleman disease (CD) is a rare pathologic process of unknown etiology, characterized by non-neoplastic lymph node enlargement. Two distinct histologic patterns are recognized; the hyaline-vascular type and the less common plasma cells type. Another intermediate type has been described. The clinical features are classified into 2 categories, localized (unicentric) and generalized (multicentric), the later associated with systemic manifestations and poor prognosis. CD affecting the central nervous system is extremely rare. We report a new case of localized intracranial CD and we accomplish a review of the literature. CASE REPORT: A 30-year-old man presented with a generalized tonic-clonic seizure. Computerized tomography and magnetic resonance imaging showed a small mass in the right temporoparietal convexity with homogenous enhancement after contrast administration. Extensive vasogenic edema in comparison with the size of the mass was also identified and based on the neuroradiologic finding, a suspected diagnosis of meningoangiomatosis was formulated. The mass was completely resected and his histologic examination identified the hyaline-vascular type of CD. One year after surgery, the patient remains seizure free, without evidence of systemic involvement or recurrence of the mass. CONCLUSIONS: Our case and review of the literature show the value of the extensive brain edema on neuroimaging finding to the differential diagnosis for a solitary mass arising from the meninges. We emphasize on the need for histologic examination when the diagnosis of meningioma is not entirely clear.