Experimental Techniques
Our work examines methods to treat conditions affecting the brain such as stroke, spinal cord injury and motoneuron disease. While we use a wide range of experimental approaches we aim to avoid using animals as much as possible. We regularly carry out non-invasive experiments in healthy human subjects and patients, and construct computer models of the brains neural systems, which we study to understand them better. However, these methods cannot always give us the information we need. For example, some of the areas which we are interested in are deep within the brain (e.g. the reticular formation), or spinal cord; these do not provide us with usable signals for many non-invasive methods.
For these reasons, we also carry out experiments in animals, where, under anaesthetic and with the supervision of a vet, we can place fine wire electrodes within the brain to record the activity of single cells. The motor system of man has some key differences in connections between brain and spinal cord compared with other species (e.g. rodents). This means that, in order for our experiments to yield data relevant to human disease, we need to work with primates.
We are proud of the excellent standards of animal welfare in our laboratories in Newcastle and we work hard to minimise the number of animals used. Monkeys are housed in pairs, allowing social interaction such as grooming, in large and interesting cages which significantly exceed minimum UK guidelines. Surgical procedures are carried out in dedicated theatre facilities, with high standards of anaesthesia. In some procedures the animal is anaesthetised, the experiment is carried out without the animal being aware, and it is not brought round from the procedure.
In other work, the animal is surgically implanted with electrodes under anaesthetic, and then allowed to recover so that we can record or stimulate the brain in the awake state – a procedure now routinely used for patients with movement disorders (deep brain stimulation Newcastle University Animal Research) but which provides us with an important insight into how this technique can be improved for human patients. There is no need for animals to suffer pain in these studies, and we use advanced modern methods for post-operative pain control: this is not just good animal welfare, but good science, since an animal in pain would not yield the data that we need. All of our work in the UK is carried out under authority of licences issued by the Home Office.
Our animal work leads to important understanding of basic neural systems, which directly leads into our studies in patients as shown by the following examples:
We have discovered a novel method to speed up the diagnosis of motor neuron disease. Thanks to our monkey studies in primates into beta-band oscillations in the motor cortex.
Studies with primates into tremor have found a novel role for the spinal cord, which may lead to improved treatments for patients with pathological tremor
Work with primates has provided important insight into how weak stimulation of the spinal cord could generate useful movements for patients paralysed by spinal cord injury (Intraspinal Microstimulation to Restore Hand Function).
We defined a role for the reticular formation in control of primate hand movements, and showed that this pathway makes an important contribution to recovery following damage such as after stroke or spinal cord injury. We are working on a method to develop new therapies to improve stroke recovery, such as a wearable electronic device. We are developing this with essential primate work which is defining how electrical stimulation can modify neural circuits.