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Immunohistochemical techniques were used to study the distributions of glutamic acid decarboxylase (GAD) and gamma-aminobutyric acid (GABA) in pigeon forebrain and midbrain to determine the organization of GABAergic systems in these brain areas in birds. In the basal ganglia, numerous medium-sized neurons throughout the striatum were labeled for GABA, while pallidal neurons, as well as a small population of large, aspiny striatal neurons, labeled for GAD and GABA. GAD+ and GABA+ fibers and terminals were abundant throughout the basal ganglia, and GABAergic fibers were found in all extratelencephalic targets of the basal ganglia. Most of these targets also contained numerous GABAergic neurons. In pallial regions, approximately 10-12% of the neurons were GABAergic. The outer rind of the pallium was more intensely labeled for GABAergic fibers than the core. The olfactory tubercle region, the ventral pallidum, and the hypothalamus were extremely densely labeled for GABAergic fibers, while GABAergic neurons were unevenly distributed in the hypothalamus. GABAergic neurons and fibers were abundant in the dorsalmost part of thalamus and the dorsal geniculate region, while GABAergic neurons and fibers were sparse (or lightly labeled) in the thalamic nuclei rotundus, triangularis, and ovoidalis. Further, GABAergic neurons were abundant in the superficial tectal layers, the magnocellular isthmic nucleus, the inferior colliculus, the intercollicular region, the central gray, and the reticular formation. GABAergic fibers were particularly abundant in the superficial tectal layers, the parvocellular isthmic nucleus, the inferior colliculus, the intercollicular region, the central gray, and the interpeduncular nucleus. These results suggest that GABA plays a role as a neurotransmitter in nearly all fore- and midbrain regions of birds, and in many instances the observed distributions of GABAergic neurons and fibers closely resemble the patterns seen in mammals, as well as in other vertebrates.

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In mammals, the subthalamic nucleus (STN) is a glutamatergic diencephalic cell group that develops in the caudal hypothalamus and migrates to a position above the cerebral peduncle. By its input from the external pallidal segment and projection to the internal pallidal segment, STN plays a critical role in basal ganglia functions. Although the basal ganglia in birds is well developed, possesses the same major neuron types as in mammals, and plays a role in movement control similar to that in mammals, it has been uncertain whether birds possess an STN. We report here evidence indicating that the so-called anterior nucleus of the ansa lenticularis (ALa) is the avian homolog of mammalian STN. First, the avian ALa too develops within the mammillary hypothalamic area and migrates to a position adjacent to the cerebral peduncle. Second, ALa specifically receives input from dorsal pallidal neurons that receive input from enkephalinergic striatal neurons, as is true of STN. Third, ALa projects back to avian dorsal pallidum, as also the case for STN in mammals. Fourth, the neurons of ALa contain glutamate, and the target neurons of ALa in dorsal pallidum possess AMPA-type glutamate receptor profiles resembling those of mammalian pallidal neurons. Fifth, unilateral lesions of ALa yield behavioral disturbances and movement asymmetries resembling those observed in mammals after STN lesions. These various findings indicate that ALa is the avian STN, and they suggest that the output circuitry of the basal ganglia for motor control is similar in birds and mammals.

Extended-spectrum b-lactamases b-lactam resistance Livestock farming Prevalence Risk factors a b s t r a c tObjectives: In the Netherlands there is an ongoing debate regarding environmental health risks of livestock farming for neighbouring residents. This explorative study aims to determine the prevalence of carriage of extended-spectrum b-lactamase and/or plasmid-mediated AmpC-producing Enterobacteriaceae (ESBL/pAmpC-E) in the general population living in a livestock-dense area, and to study associations between determinants, including exposure through contact with animals and the environment, and human carriage of ESBL/pAmpC-E. Methods: A cross-sectional study was performed among 2432 adults (aged 20e72 years) in 12 temporary research centres in the south of the Netherlands, consisting of a questionnaire and analysis of a faecal sample to assess carriage of ESBL/pAmpC-E. Risk factors were analysed using logistic regression. Results: The prevalence for carriage of ESBL/pAmpC-E was 4.5% (109/2432; 95% CI 3.7e5.4) ranging from 1.4% to 10.9% among the research centres. ESBL/pAmpC resistance genes were detected in Escherichia coli and Klebsiella pneumoniae isolates obtained from these 109 persons and the most common ESBLresistance genes were bla CTX-M-15 , bla CTX-M-14/17 and bla CTX-M-1 , originating from 76 participants. Travel in the previous 12 months to Africa, Asia or Latin America (OR 2.82; 95% CI 1.71e4.63), having kept cows for a hobby in the previous 5 years (OR 3.77; 95% CI 1.22e11.64), usage of proton-pump inhibitors (OR 1.84; 95% CI 1.05e3.23), and living within 1000 m of a mink farm (OR 2.26; 95% CI 1.28e3.98) were identified as risk factors. Exposure to poultry was not identified as a risk factor. Conclusions: Overall, living in close proximity to livestock animals and farms does not seem to be a risk factor for carriage of ESBL/pAmpC-E. C.C.H. Wielders, CMI 2017;23:120.e1e120.e8