ABSTRACT
The macroscale neuronal connections of the lateral preoptic area (LPO) and the caudally adjacent lateral hypothalamic area anterior region (LHAa) were investigated in mice by anterograde and retrograde axonal tracing. Both hypothalamic regions are highly and diversely connected, with connections to >200 gray matter regions spanning the forebrain, midbrain, and rhombicbrain. Intrahypothalamic connections predominate, followed by connections with the cerebral cortex and cerebral nuclei. A similar overall pattern of LPO and LHAa connections contrasts with substantial differences between their input and output connections. Strongest connections include outputs to the lateral habenula, medial septal and diagonal band nuclei, and inputs from rostral and caudal lateral septal nuclei; however, numerous additional robust connections were also observed. The results are discussed in relation to a current model for the mammalian forebrain network that associates LPO and LHAa with a range of functional roles, including reward prediction, innate survival behaviors (including integrated somatomotor and physiological control), and affect. The present data suggest a broad and intricate role for LPO and LHAa in behavioral control, similar in that regard to previously investigated LHA regions, contributing to the finely tuned sensory-motor integration that is necessary for behavioral guidance supporting survival and reproduction.
Subject(s)
Preoptic Area , Septal Nuclei , Animals , Cerebral Cortex , Hypothalamic Area, Lateral , Hypothalamus , Mammals , MiceABSTRACT
The cortico-basal ganglia-thalamo-cortical loop is one of the fundamental network motifs in the brain. Revealing its structural and functional organization is critical to understanding cognition, sensorimotor behaviour, and the natural history of many neurological and neuropsychiatric disorders. Classically, this network is conceptualized to contain three information channels: motor, limbic and associative1-4. Yet this three-channel view cannot explain the myriad functions of the basal ganglia. We previously subdivided the dorsal striatum into 29 functional domains on the basis of the topography of inputs from the entire cortex5. Here we map the multi-synaptic output pathways of these striatal domains through the globus pallidus external part (GPe), substantia nigra reticular part (SNr), thalamic nuclei and cortex. Accordingly, we identify 14 SNr and 36 GPe domains and a direct cortico-SNr projection. The striatonigral direct pathway displays a greater convergence of striatal inputs than the more parallel striatopallidal indirect pathway, although direct and indirect pathways originating from the same striatal domain ultimately converge onto the same postsynaptic SNr neurons. Following the SNr outputs, we delineate six domains in the parafascicular and ventromedial thalamic nuclei. Subsequently, we identify six parallel cortico-basal ganglia-thalamic subnetworks that sequentially transduce specific subsets of cortical information through every elemental node of the cortico-basal ganglia-thalamic loop. Thalamic domains relay this output back to the originating corticostriatal neurons of each subnetwork in a bona fide closed loop.
Subject(s)
Basal Ganglia/cytology , Cerebral Cortex/cytology , Neural Pathways , Neurons/cytology , Thalamus/cytology , Animals , Basal Ganglia/anatomy & histology , Cerebral Cortex/anatomy & histology , Male , Mice , Mice, Inbred C57BL , Thalamus/anatomy & histologyABSTRACT
Whole apple extracts possess potent antioxidant activity and antiproliferative activity against cancer cells in vitro. The objectives of this study were to determine the anticancer activity of apple extracts in a rat mammary cancer model induced by 7,12-dimethylbenz(a)anthracene (DMBA) in vivo and to determine if apple extracts inhibited cell proliferation and affected apoptosis in mammary cancer tissues in vivo. Rats were given the whole apple extracts (0, 3.3, 10.0, or 20.0 g/kg of body weight) by gavage starting 2 weeks prior to DMBA administration and continuing for 24 weeks. Rats treated with DMBA (positive control) developed mammary tumors with 71.4% tumor incidence during the 24-week study. No tumors were detected in the negative control group untreated with DMBA. A dose-dependent inhibition of mammary carcinogenesis by apple extracts was observed (P < 0.01). Tumor multiplicity decreased with increasing apple extracts. Histopathological evaluations of tumors were performed. The proportions of adenocarcinoma masses decreased with increasing apple extracts. The expression of proliferating cell nuclear antigen (PCNA), cyclin D1, and Bcl-2 decreased, and Bax expression and apoptosis increased with increasing apple extracts. These results demonstrate the potent capacity of fresh apples to suppress DMBA-initiated mammary cancers in rats.
Subject(s)
Anticarcinogenic Agents/administration & dosage , Apoptosis/drug effects , Fruit/chemistry , Malus/chemistry , Mammary Neoplasms, Animal/prevention & control , Plant Extracts/administration & dosage , 9,10-Dimethyl-1,2-benzanthracene , Animals , Cell Division/drug effects , Female , Mammary Neoplasms, Animal/chemically induced , Mammary Neoplasms, Animal/pathology , Phytotherapy , Rats , Rats, Sprague-DawleyABSTRACT
The overall projection pattern of a tiny bed nuclei of the stria terminalis anteromedial group differentiation, the dorsomedial nucleus (BSTdm), was analyzed with the Phaseolus vulgaris-leucoagglutinin anterograde pathway tracing method in rats. Many brain regions receive a relatively moderate to strong input from the BSTdm. They fall into eight general categories: humeral sensory-related (subfornical organ and median preoptic nucleus, involved in initiating drinking behavior and salt appetite), neuroendocrine system (magnocellular: oxytocin, vasopressin; parvicellular: gonadotropin-releasing hormone, somatostatin, thyrotropin-releasing hormone, corticotropin-releasing hormone), central autonomic control network (central amygdalar nucleus, BST anterolateral group, descending paraventricular hypothalamic nucleus, retrochiasmatic area, ventrolateral periaqueductal gray, Barrington's nucleus), hypothalamic visceromotor pattern-generator network (five of six known components), behavior control column (ingestive: descending paraventricular nucleus; reproductive: lateral medial preoptic nucleus; defensive: anterior hypothalamic nucleus; foraging: ventral tegmental area, along with interconnected nucleus accumbens and substantia innominata), orofacial motor control (retrorubral area), thalamocortical feedback loops (paraventricular, central medial, intermediodorsal, and medial mediodorsal nuclei; nucleus reuniens), and behavioral state control (subparaventricular zone, ventrolateral preoptic nucleus, tuberomammillary nucleus, supramammillary nucleus, lateral habenula, and raphé nuclei). This pattern of axonal projections, and what little is known of its inputs suggest that the BSTdm is part of a striatopallidal differentiation involved in coordinating the homeostatic and behavioral responses associated thirst and salt appetite, although clearly it may relate them to other functions as well. The BSTdm generates the densest known inputs directly to the neuroendocrine system from any part of the cerebral hemispheres.
Subject(s)
Brain Mapping , Drinking/physiology , Mediodorsal Thalamic Nucleus/anatomy & histology , Neural Pathways/anatomy & histology , Septal Nuclei/anatomy & histology , Animals , Brain Stem/cytology , Brain Stem/metabolism , Functional Laterality , Humans , Hypothalamus/cytology , Hypothalamus/metabolism , Models, Biological , Neurosecretory Systems/physiology , Phytohemagglutinins/metabolism , Rats , Rats, Sprague-DawleyABSTRACT
The basic structural organization of axonal projections from the small but distinct magnocellular and ventral nuclei (of the bed nuclei of the stria terminalis) was analyzed with the Phaseolus vulgaris leucoagglutinin anterograde tract tracing method in adult male rats. The former's overall projection pattern is complex, with over 80 distinct terminal fields ipsilateral to injection sites. Innervated regions in the cerebral hemisphere and brainstem fall into nine general functional categories: cerebral nuclei, behavior control column, orofacial motor-related, humorosensory/thirst-related, brainstem autonomic control network, neuroendocrine, hypothalamic visceromotor pattern-generator network, thalamocortical feedback loops, and behavioral state control. The most novel findings indicate that the magnocellular nucleus projects to virtually all known major parts of the brain network that controls pelvic functions, including micturition, defecation, and penile erection, as well as to brain networks controlling nutrient and body water homeostasis. This and other evidence suggests that the magnocellular nucleus is part of a corticostriatopallidal differentiation modulating and coordinating pelvic functions with the maintenance of nutrient and body water homeostasis. Projections of the ventral nucleus are a subset of those generated by the magnocellular nucleus, with the obvious difference that the ventral nucleus does not project detectably to Barrington's nucleus, the subfornical organ, the median preoptic and parastrial nuclei, the neuroendocrine system, and midbrain orofacial motor-related regions.
Subject(s)
Brain Mapping , Hypothalamus/cytology , Mediodorsal Thalamic Nucleus/anatomy & histology , Neural Pathways/anatomy & histology , Septal Nuclei/anatomy & histology , Animals , Hypothalamus/metabolism , Male , Models, Anatomic , Neural Networks, Computer , Neurosecretory Systems , Penile Erection , Phytohemagglutinins/metabolism , Rats , Rats, Sprague-Dawley , Thalamus/cytology , Thalamus/metabolismABSTRACT
The anteromedial area of the bed nuclei of the stria terminalis (BSTam) is the relatively undifferentiated region of the anterior medial (anteromedial) group of the bed nuclei of the stria terminalis (BSTamg), which also includes the more distinct dorsomedial, magnocellular, and ventral nuclei. The overall pattern of axonal projections from the rat BSTam was analyzed with the Phaseolus vulgaris-leucoagglutinin anterograde pathway tracing method. Brain areas receiving relatively moderate to strong inputs from the BSTam fall into five general categories: neuroendocrine system (regions containing pools of magnocellular oxytocin neurons, and parvicellular corticotropin-releasing hormone, thyrotropin-releasing hormone, somatostatin, and dopamine neurons); central autonomic control network (central amygdalar nucleus, descending paraventricular nucleus, and ventrolateral periaqueductal gray); hypothalamic visceromotor pattern generator network (five of six known components); behavior control column (descending paraventricular nucleus and associated arcuate nucleus; ventral tegmental area and associated nucleus accumbens and substantia innominata); and behavioral state control (supramammillary and tuberomammillary nuclei). The BSTam projects lightly to thalamocortical feedback loops (via the medial-midline-intralaminar thalamus). Its pattern of axonal projections, combined with its pattern of neural inputs (the most varied of all BST cell groups), suggests that the BSTam is part of a striatopallidal differentiation involved in coordinating neuroendocrine, autonomic, and behavioral or somatic responses associated with maintaining energy balance homeostasis.
Subject(s)
Brain Mapping , Hypothalamus/cytology , Mediodorsal Thalamic Nucleus/anatomy & histology , Neural Pathways/anatomy & histology , Septal Nuclei/anatomy & histology , Animals , Autonomic Nervous System/physiology , Behavior, Animal/physiology , Endocrine System/physiology , Energy Metabolism/physiology , Hypothalamus/metabolism , Male , Neural Networks, Computer , Neurons/metabolism , Phytohemagglutinins/metabolism , Rats , Rats, Sprague-Dawley , Septal Nuclei/cytology , Thalamus/cytology , Thalamus/metabolismABSTRACT
In mammals, innate reproductive and defensive behaviors are mediated by anatomically segregated connections between the amygdala and hypothalamus. This anatomic segregation poses the problem of how the brain integrates activity in these circuits when faced with conflicting stimuli eliciting such mutually exclusive behaviors. Using genetically encoded and conventional axonal tracers, we have found that the transcription factor Lhx6 delineates the reproductive branch of this pathway. Other Lhx proteins mark neurons in amygdalar nuclei implicated in defense. We have traced parallel projections from the posterior medial amygdala, activated by reproductive or defensive olfactory stimuli, respectively, to a point of convergence in the ventromedial hypothalamus. The opposite neurotransmitter phenotypes of these convergent projections suggest a "gate control" mechanism for the inhibition of reproductive behaviors by threatening stimuli. Our data therefore identify a potential neural substrate for integrating the influences of conflicting behavioral cues and a transcription factor family that may contribute to the development of this substrate.