A simple intracranial cannula for the rat

STK3/STK4 signalling in adipocytes regulates mitophagy and energy expenditure

Obesity reduces adipocyte mitochondrial function, and expanding adipocyte oxidative capacity is an emerging strategy to improve systemic metabolism. Here, we report that serine/threonine-protein kinase 3 (STK3) and STK4 are key physiological suppressors of mitochondrial capacity in brown, beige and white adipose tissues. Levels of STK3 and STK4, kinases in the Hippo signalling pathway, are greater in white than brown adipose tissues, and levels in brown adipose tissue are suppressed by cold exposure and greatly elevated by surgical denervation. Genetic inactivation of Stk3 and Stk4 increases mitochondrial mass and function, stabilizes uncoupling protein 1 in beige adipose tissue and confers resistance to metabolic dysfunction induced by high-fat diet feeding. Mechanistically, STK3 and STK4 increase adipocyte mitophagy in part by regulating the phosphorylation and dimerization status of the mitophagy receptor BNIP3. STK3 and STK4 expression levels are elevated in human obesity, and pharmacological inhibition improves metabolic profiles in a mouse model of obesity, suggesting STK3 and STK4 as potential targets for treating obesity-related diseases.

A reliable, rapid and inexpensive method for producing and implanting chronic cannulae into brains of small animals

A new method for constructing and implanting cannulae into brains of small animals is described. This system allows drug microinjections to be performed on multiple occasions with little tissue damage, at a very low cost.

An easily constructed durable chronic intracerebral cannula system

A simple, inexpensive, and rugged intracerebral cannula system is described and construction details are provided for both guide and injection cannula assemblies. The guide cannula assembly is easily and quickly molded from dental acrylic cement and has a protective acrylic collar surrounding the end of the actual guide cannula. This system is believed to offer some advantage over current methodologies in terms of expense, durability and ease of construction and is well suited to use in rodents.

[Effects of hypothalamus and globus pallidus lesions and of apomorphine injections into the globus pallidus, caudate nucleus, substantia nigra and septum on the aggressive behavior induced by apomorphine treatment of rats (author's transl)]

Intraspecific apomorphine-induced aggressive behavior in the rat was not affected following electrolytic lesions of the ventromedial hypothalamus. Some inhibition of the aggressive behavior was found after lateral lesions and an almost total suppression after destruction of globus pallidus. These results, as well as those following localized injections of apomorphine into the septum, substantia nigra, caudate nucleus, and globus pallidus suggested that the latter anatomical region may be the major site of the action of apomorphine in the behavior studies. The role of acetylcholine is discussed.

A permanent plastic cannula for intraventricular injections into rat brain

The construction and use of a permanent, implanted plastic camnula for intraventricular injections in rat brain is described. The cannula can be used in either acute or chronic experiments.