Rapid prototyping for neuroscience and neural engineering.

Rapid prototyping (RP) is a useful method for designing and fabricating a wide variety of devices used for neuroscience research. The present study confirms the utility of using fused deposition modeling, a specific form of RP, to produce three devices commonly used for basic science experimentation. The accuracy and precision of the RP method varies according to the type and quality of the printer as well as the thermoplastic substrate.

A method for monitoring intra-cortical motor cortex responses in an animal model of ischemic stroke.

Neuroplasticity is believed to play a key role in functional recovery after stroke. Neuroplastic effects can be monitored at the cellular level via e.g.

Fast wave propagation in auditory cortex of an awake cat using a chronic microelectrode array.

We investigated fast wave propagation in auditory cortex of an alert cat using a chronically implanted microelectrode array. A custom, real-time imaging template exhibited wave dynamics within the 33-microwire array (3 mm(2)) during ten recording sessions spanning 1 month post implant. Images were based on the spatial arrangement of peri-stimulus time histograms at each recording site in response to auditory stimuli consisting of tone pips between 1 and 10 kHz at 75 dB SPL.

Modified spike-triggered averaging to assess rat auditory cortex time-frequency receptive fields.

Receptive fields have been used as a tool to study the functional organization of the auditory system in several animals. In this study, they have been used to characterize the primary auditory cortex of rats, specifically to address the differences in auditory processing at different depths of the cortex. The depths chosen; 500, 800 and 1300 microm correspond to layers IV, V and VI of the cortex.

Preliminary study of neurite outgrowth within polyimide microtubes.

The cone electrode first developed by P.R. Kennedy paved headway in the area of cortical prostheses.

Electrophysiological response dynamics during focal cortical infarction.

While the intracellular processes of hypoxia-induced necrosis and the intercellular mechanisms of post-ischemic neurotoxicity associated with stroke are well documented, the dynamic electrophysiological (EP) response of neurons within the core or periinfarct zone remains unclear. The present study validates a method for continuous measurement of the local EP responses during focal cortical infarction induced via photothrombosis. Single microwire electrodes were acutely implanted into the primary auditory cortex of eight rats.

On variability and use of rat primary motor cortex responses in behavioral task discrimination.

The success of a cortical motor neuroprosthetic system will rely on the system's ability to effectively execute complex motor tasks in a changing environment. Invasive, intra-cortical electrodes have been successfully used to predict joint movement and grip force of a robotic arm/hand with a non-human primate (Chapin J K, Moxon K A, Markowitz R S and Nicolelis M A L 1999 Real-time control of a robotic arm using simultaneously recorded neurons in the motor cortex Nat. Neurosci.

Microstimulation in auditory cortex provides a substrate for detailed behaviors.

Sensory cortical prostheses have potential to aid people suffering from blindness, deafness and other sensory deficits. However, research to date has shown that sensation thresholds via epicortical stimulation are surprisingly large. These thresholds result in potentially deleterious electrical currents, as well as large activation volumes.

Cortical microstimulation in auditory cortex of rat elicits best-frequency dependent behaviors.

Electrical activation of the auditory cortex has been shown to elicit an auditory sensation; however, the perceptual effects of auditory cortical microstimulation delivered through penetrating microelectrodes have not been clearly elucidated. This study examines the relationship between electrical microstimulus location within the adult rat auditory cortex and the subsequent behavior induced. Four rats were trained on an auditory frequency discrimination task and their lever-pressing behavior in response to stimuli of intermediate auditory frequencies was quantified.

Decoding of auditory cortex signals with a LAMSTAR neural network.

Objectives: Each neuron has a specific set of stimuli, which it preferentially responds to (the receptive field of the neuron). For implantable cortical prosthetic devices specific points of the cortex (or groups of neurons) have to be stimulated to create perceptions of sensory stimulus with specific attributes (such as frequency, temporal characteristics, etc). Such applications would need real time decoding of signals.

Single electrode micro-stimulation of rat auditory cortex: an evaluation of behavioral performance.

A combination of electrophysiological mapping, behavioral analysis and cortical micro-stimulation was used to explore the interrelation between the auditory cortex and behavior in the adult rat. Auditory discriminations were evaluated in eight rats trained to discriminate the presence or absence of a 75 dB pure tone stimulus. A probe trial technique was used to obtain intensity generalization gradients that described response probabilities to mid-level tones between 0 and 75 dB.