Fast-spike interneurons in visual cortical layer 5: Heterogeneous response properties are related to thalamocortical connectivity.

Layer 4 of rabbit V1 contains fast-spiking GABAergic interneurons (suspected inhibitory interneurons, SINs) that receive potent synaptic input from the LGN and generate fast, local feed-forward inhibition. These cells display receptive fields with overlapping ON/OFF subregions, non-linear spatial summation, very broad orientation/directional tuning, and high spontaneous and visually-driven firing rates. Such fast-spike interneurons are also found in layer 5 (L5), which receives a much sparser input from the LGN, but the response properties and thalamocortical connectivity of L5 SINs are relatively unstudied.

Retinal direction of motion is reliably transmitted to visual cortex through highly selective thalamocortical connections.

Motion perception is crucial to animal survival and effective environmental interactions. In mammals, detection of movement begins in the retina. Directionally selective (DS) retinal ganglion cells were first discovered in the rabbit eye, and they have since been found in mouse, cat, and monkey.

Macrocyclic Copper(II) Complexes as Catalysts for Electrochemically Mediated Atom Transfer.

Copper-catalyzed electrochemical atom transfer radical addition (ATRA) is a new method for the creation of new C-C bonds under mild conditions. In this work, we have explored the reactivity of an analogous series of N macrocyclic Cu complexes as ATRA precatalysts, which are primed by reduction to their monovalent oxidation state. These complexes were fully characterized structurally, spectroscopically, and electrochemically.

The (±)-5-Aza[1.0]triblattane Skeleton via Azetine Cycloaddition.

The first synthesis of the 5-aza[1.0]triblattane skeleton was achieved through a [4 + 2] cycloaddition approach using a suitably protected azetine and cyclopentadiene. A series of azetines were synthesized to explore both stability and suitable N-protection.

Electrocatalytic Atom Transfer Radical Addition with Turbocharged Organocopper(II) Complexes.

The utility and scope of Cu-catalyzed halogen atom transfer chemistry have been exploited in the fields of atom transfer radical polymerization and atom transfer radical addition, where the metal plays a key role in radical formation and minimizing unwanted side reactions. We have shown that electrochemistry can be employed to modulate the reactivity of the Cu catalyst between its active (Cu) and dormant (Cu) states in a variety of ligand systems. In this work, a macrocyclic pyridinophane ligand (L1) was utilized, which can break the C-Br bond of BrCHCN to release CHCN radicals when in complex with Cu.

Organocopper(ii) complexes: new catalysts for carbon-carbon bond formation electrochemical atom transfer radical addition (ATRA).

Organocopper(ii) complexes are a rarity while organocopper(i) complexes are commonplace in chemical synthesis. In the course of building a strategy to generate organocopper(ii) species utilizing electrochemistry, a method to form compounds with Cu-C bonds was discovered, that demonstrated remarkably potent reactivity towards different functionalized alkenes under catalytic control. The role of the organocopper(ii) complex is to act as a source of masked radicals (in this case ˙CHCN) that react with an alkene to generate the corresponding γ-halonitrile in good yields through atom transfer radical addition (ATRA) to various alkenes.

Activation of a Visual Cortical Column by a Directionally Selective Thalamocortical Neuron.

The retinas of rabbits and rodents have directionally selective (DS) retinal ganglion cells that convey directional signals through the lateral geniculate nucleus (LGN) of the thalamus to the primary visual cortex (V1). Notably, the function and synaptic impact in V1 of these directional LGN signals are unknown. Here we measured, in awake rabbits, the synaptic impact generated in V1 by individual LGN DS neurons.