Trainees in the Horn laboratory learn about cellular and molecular mechanisms of synaptic transmission,
the computational analysis of cells and circuits, and systems neuroscience. Research projects for all of our
trainees are designed to match their experience level, interests and career goals. Our current projects
incorporate the following goals and methods:
- To compare synaptic gain in different neuronal cell types using the dynamic clamp method to create
omputer-generated virtual nicotinic synapses on living sympathetic neurons. One goal is to test the hypothesis
that synaptic gain is greater in vasomotor than secretomotor circuits, using bullfrog sympathetic ganglia as a
- To determine how calcium-dependent mechanisms triggered by postsynaptic activity regulate synaptic gain.
- To compare synaptic integration in identified subclasses of mammalian sympathetic neurons using the rat
superior sympathetic ganglion as a model system. These experiments use intact ganglia and primary cell
cultures. The methods include intracellular recording, extracellular recording, confocal cell reconstructions
and immunocytochemical detection of phenotypic markers.
- To analyze how muscarinic, adrenergic and peptidergic neuromodulatory mechanisms regulate synaptic gain.
- To analyze the role of oscillatory activity and neuronal synchronization in regulating synaptic integration
in sympathetic ganglia. This project combines mathematical simulations in MATLAB with dynamic-clamp
- To analyze the role of A-type potassium channels in the regulation of pacemaker activity in midbrain
dopamine neurons. For these experiments, whole-cell patch-clamp recording and dynamic-clamp methodology are
used to study neurons in rat brain slices.
- To understand how neurotransmitters control the inter-conversion of pacemaker and burst firing by dopamine
neurons and to identify specializations of firing that distinguish dopamine neurons in the ventral tegmental
area from those in the substantia nigra.