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A Cerebellar Neuroprosthetic System: Computational Architecture and in vivo Test.

Herreros I, Giovannucci A, Taub AH, Hogri R, Magal A, Bamford S, Prueckl R, Verschure PF - Front Bioeng Biotechnol (2014)

Bottom Line: As a result, we show that the anesthetized rat, equipped with our neuroprosthetic system, can be classically conditioned to the acquisition of an eye-blink response.The resulting system represents an important step toward replacing lost functions of the central nervous system via neuroprosthetics, obtained by integrating a synthetic circuit with the afferent and efferent pathways of a damaged brain region.These results also embody an early example of science-based medicine, where on the one hand the neuroprosthetic system directly validates a theory of cerebellar learning that informed the design of the system, and on the other one it takes a step toward the development of neuro-prostheses that could recover lost learning functions in animals and, in the longer term, humans.

View Article: PubMed Central - PubMed

Affiliation: Synthetic Perceptive, Emotive and Cognitive Systems group (SPECS), Universitat Pompeu Fabra , Barcelona , Spain.

ABSTRACT
Emulating the input-output functions performed by a brain structure opens the possibility for developing neuroprosthetic systems that replace damaged neuronal circuits. Here, we demonstrate the feasibility of this approach by replacing the cerebellar circuit responsible for the acquisition and extinction of motor memories. Specifically, we show that a rat can undergo acquisition, retention, and extinction of the eye-blink reflex even though the biological circuit responsible for this task has been chemically inactivated via anesthesia. This is achieved by first developing a computational model of the cerebellar microcircuit involved in the acquisition of conditioned reflexes and training it with synthetic data generated based on physiological recordings. Secondly, the cerebellar model is interfaced with the brain of an anesthetized rat, connecting the model's inputs and outputs to afferent and efferent cerebellar structures. As a result, we show that the anesthetized rat, equipped with our neuroprosthetic system, can be classically conditioned to the acquisition of an eye-blink response. However, non-stationarities in the recorded biological signals limit the performance of the cerebellar model. Thus, we introduce an updated cerebellar model and validate it with physiological recordings showing that learning becomes stable and reliable. The resulting system represents an important step toward replacing lost functions of the central nervous system via neuroprosthetics, obtained by integrating a synthetic circuit with the afferent and efferent pathways of a damaged brain region. These results also embody an early example of science-based medicine, where on the one hand the neuroprosthetic system directly validates a theory of cerebellar learning that informed the design of the system, and on the other one it takes a step toward the development of neuro-prostheses that could recover lost learning functions in animals and, in the longer term, humans.

No MeSH data available.


Related in: MedlinePlus

Event detections and triggers during the online experiment. Raster plot with the PN detections (blue dots; well-timed PNs are thicker), IO detections (black), and CR triggers (blue dots; well-timed triggers are thicker). The CS (yellow area) and US (pink area) periods are indicated. Blue line separates well-timed from late CRs. The horizontal dashed red line separates acquisition and extinction phases.
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Figure 11: Event detections and triggers during the online experiment. Raster plot with the PN detections (blue dots; well-timed PNs are thicker), IO detections (black), and CR triggers (blue dots; well-timed triggers are thicker). The CS (yellow area) and US (pink area) periods are indicated. Blue line separates well-timed from late CRs. The horizontal dashed red line separates acquisition and extinction phases.

Mentions: After the preliminary assessment of the quality of the biosignals, we proceeded with the online classical conditioning experiment (Figure 11). The experiment lasted 1 h 20 min and comprised 190 CS–US stimulation trials (acquisition) followed by 180 CS-alone trials (extinction), with randomized ITIs between 10 and 15 s. In Figure 11, we display events detected and stimulations triggered by the neuroprosthetic system. For the whole experiment, in the PN there was a TDR in of 75.5% and a FAR of 0.1 Hz that include a high number of late CS-detections (Figure 11). Notably, the number of PN detections during baseline was very low (only five false alarms in 80 min). In the IO, we obtained a TDR of 38% and a FAR of 1.2 Hz.


A Cerebellar Neuroprosthetic System: Computational Architecture and in vivo Test.

Herreros I, Giovannucci A, Taub AH, Hogri R, Magal A, Bamford S, Prueckl R, Verschure PF - Front Bioeng Biotechnol (2014)

Event detections and triggers during the online experiment. Raster plot with the PN detections (blue dots; well-timed PNs are thicker), IO detections (black), and CR triggers (blue dots; well-timed triggers are thicker). The CS (yellow area) and US (pink area) periods are indicated. Blue line separates well-timed from late CRs. The horizontal dashed red line separates acquisition and extinction phases.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126458&req=5

Figure 11: Event detections and triggers during the online experiment. Raster plot with the PN detections (blue dots; well-timed PNs are thicker), IO detections (black), and CR triggers (blue dots; well-timed triggers are thicker). The CS (yellow area) and US (pink area) periods are indicated. Blue line separates well-timed from late CRs. The horizontal dashed red line separates acquisition and extinction phases.
Mentions: After the preliminary assessment of the quality of the biosignals, we proceeded with the online classical conditioning experiment (Figure 11). The experiment lasted 1 h 20 min and comprised 190 CS–US stimulation trials (acquisition) followed by 180 CS-alone trials (extinction), with randomized ITIs between 10 and 15 s. In Figure 11, we display events detected and stimulations triggered by the neuroprosthetic system. For the whole experiment, in the PN there was a TDR in of 75.5% and a FAR of 0.1 Hz that include a high number of late CS-detections (Figure 11). Notably, the number of PN detections during baseline was very low (only five false alarms in 80 min). In the IO, we obtained a TDR of 38% and a FAR of 1.2 Hz.

Bottom Line: As a result, we show that the anesthetized rat, equipped with our neuroprosthetic system, can be classically conditioned to the acquisition of an eye-blink response.The resulting system represents an important step toward replacing lost functions of the central nervous system via neuroprosthetics, obtained by integrating a synthetic circuit with the afferent and efferent pathways of a damaged brain region.These results also embody an early example of science-based medicine, where on the one hand the neuroprosthetic system directly validates a theory of cerebellar learning that informed the design of the system, and on the other one it takes a step toward the development of neuro-prostheses that could recover lost learning functions in animals and, in the longer term, humans.

View Article: PubMed Central - PubMed

Affiliation: Synthetic Perceptive, Emotive and Cognitive Systems group (SPECS), Universitat Pompeu Fabra , Barcelona , Spain.

ABSTRACT
Emulating the input-output functions performed by a brain structure opens the possibility for developing neuroprosthetic systems that replace damaged neuronal circuits. Here, we demonstrate the feasibility of this approach by replacing the cerebellar circuit responsible for the acquisition and extinction of motor memories. Specifically, we show that a rat can undergo acquisition, retention, and extinction of the eye-blink reflex even though the biological circuit responsible for this task has been chemically inactivated via anesthesia. This is achieved by first developing a computational model of the cerebellar microcircuit involved in the acquisition of conditioned reflexes and training it with synthetic data generated based on physiological recordings. Secondly, the cerebellar model is interfaced with the brain of an anesthetized rat, connecting the model's inputs and outputs to afferent and efferent cerebellar structures. As a result, we show that the anesthetized rat, equipped with our neuroprosthetic system, can be classically conditioned to the acquisition of an eye-blink response. However, non-stationarities in the recorded biological signals limit the performance of the cerebellar model. Thus, we introduce an updated cerebellar model and validate it with physiological recordings showing that learning becomes stable and reliable. The resulting system represents an important step toward replacing lost functions of the central nervous system via neuroprosthetics, obtained by integrating a synthetic circuit with the afferent and efferent pathways of a damaged brain region. These results also embody an early example of science-based medicine, where on the one hand the neuroprosthetic system directly validates a theory of cerebellar learning that informed the design of the system, and on the other one it takes a step toward the development of neuro-prostheses that could recover lost learning functions in animals and, in the longer term, humans.

No MeSH data available.


Related in: MedlinePlus