Science Bites seeks to compile the latest scientific research updates in bite-sized forms.

1. 3D printed brain-like tissue for neurotransmitter production

Armed with a 3D printer and bio-ink made from stem cells, Australian scientists have created brain-like tissue in a breakthrough research. The unique bio-ink is composed of human induced pluripotent stem cells (iPSC) – possessing the same properties as embryonic stem cells – capable of transforming into any cell (and organ) in the body.

Lead researcher Jeremy Crook, from the University of Wollongong and ARC Centre of Excellence for Electromaterials Science, said the ability to customise brain tissue from a person's own body tissue proved superior for transplantation. “That circumvents issues of immune rejection, which is common in organ transplantation,” he added.

Dr Crook explained the roles of neurotransmitters and their imbalance in the brain accounting for many neuropsychiatric disorders. For example, faulty serotonin and GABA-producing nerve cells are linked to schizophrenia and epilepsy, while faulty dopamine-producing cells are implicated in Parkinson's disease.

As published in the Advanced Healthcare Material journal, the team used 3D printing to create neurones involved in producing GABA and serotonin in addition to neuroglia.

3D printing with bio-ink. Photo credit: Advanced Materials/University of Wollongong/ABC News
3D printing with bio-ink. Photo credit: Advanced Materials/University of Wollongong/ABC News

Plans to print neurones that produce dopamine are in the pipeline, says the team. “We might want to make a tissue that specifically generates that neurotransmitter for grafting into the brain of a Parkinson's patient. That's absolutely achievable,” affirmed Dr Crook.

Tissue engineer Makoto Nakamura from Toyama University in Japan said the study was “very impressive” – but relayed concerns regarding the risks involved with this technology. Due to its potential to develop into teratomas, he emphasised on ensuring all stem cells had turned into nerve cells in the final stage of transplanted material.

2. Novel brain cells as targets to control hunger

In an attempt to create a novel approach to tackling obesity, researchers have discovered cells in the brain that may help control the hunger impulse. This furthers solidifies evidence that eating is a complex biological behaviour.

“We have identified two new populations of cells in the brain that potently regulate appetite,” shared study researcher Alexander Nectow. As published in the journal, Cell, scientists scrutinise the dorsal raphe nucleus (DRN) in the brainstem – where two types of cells are found.

Scientists believe new drugs could be developed to treat obesity by targeting those cells to control hunger signals. Dr Nectow discovered the activation of the DRN section when the mice were hungry. Upon imaging other mice, which were given a larger portion of food than usual, an altered pattern of DRN activity was picked up. This indicates that feeding behaviour is affected by neurons in this section of the brain.

Different brain regions are activated in mice that are well fed (left) and hungry (right). Photo credit: The Rockefeller University
Different brain regions are activated in mice that are well fed (left) and hungry (right). Photo credit: The Rockefeller University

“There are two possibilities when you see something like that. One is that the cells are just along for the ride – they are getting activated by hunger; but they’re not actually driving the food intake process. The other possibility is that they are in fact part of the sense-and-respond mechanism to hunger – and in this case, we suspect the latter,” shared Dr Nectow.

This pertinent health issue is vital to address as pointed out in a paper published in the Lancet: one-fifth of the world’s adults are expected to be obese by 2025.

3. Mathematical modelling to ultimately reduce number of seizures

Epilepsy, the debilitating condition affecting 1/100 people worldwide, now has a potentially refined investigative and treatment approach. An international team of researchers have come up with a new technique to identify regions of the brain most attributed to patients’ individual epileptic seizures.

“What is truly exciting about our findings is the opportunity that such a method offers to identify the specific brain regions involved in the generation of seizures, which in turn can provide guidance on how to optimize surgical interventions to stop seizures,” remarked lead strategist Marinho Lopes of the University of Exeter in the UK.

The researchers initially examined a database of electrocardiogram (EEG) recordings from 16 epileptic patients who had already undergone surgical treatment for their seizures. From this, the team found some brain regions portrayed greater intra- and inter-connections compared to other regions. This well-connected network is called a “rich club”.

Using a mathematical modelling technique, the team later predicted that targeting rich clubs – by eliminating the well-connected nodes – could decrease seizure quantities. Practising this strategy on the 16 patients proved successful – when surgery removed a greater proportion of the rich club (unique in each patient), fewer or no seizures occurred in the long-term.

These researchers plan to include more patients in future trials and integrate information from other brain imaging systems. MIMS

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