From: mk_thisisit
Biological processors are groundbreaking systems made from living cells, a feat previously unaccomplished in history [00:00:01], [00:00:05], [00:10:53], [00:10:57]. Swiss biocomputing startup Final Spark, founded in 2014, is the first in the world to build a living processor from living neurons [00:01:05], [00:01:08], [00:01:11].
What is a Human Brain Organoid?
A human brain organoid is essentially a small fragment of nervous tissue composed of neurons derived from humans [00:01:26], [00:01:28], [00:01:31]. While many researchers globally work on human brain organoids [00:02:08], what makes Final Spark unique is their purpose: using these organoids for computing [00:02:26], [00:02:29]. This approach is based on the assumption that human neurons can be used for computation [00:02:49], [00:02:51].
Creation and Cultivation of Organoids
Human cells are purchased from specialized companies that produce pluripotent stem cells [00:03:04], [00:03:07], [00:03:10]. These cells are typically derived from fibroblasts (skin cells) that are reprogrammed to a state of pluripotency, meaning they can develop into any cell type [00:03:13], [00:03:16], [00:03:19], [00:03:22], [00:03:25].
Differentiation into Neurons
Methods exist to differentiate skin cells into neurons [00:03:36], [00:03:39]. Specific molecules in the culture medium are used to induce these pluripotent stem cells to transform into neurons, astrocytes, and other types of brain cells [00:03:51], [00:03:54], [00:03:58], [00:04:01], [00:04:04], [00:04:07], [00:04:08], [00:04:11], [00:04:13], [00:04:17]. The cells then reorganize themselves into three-dimensional structures that functionally resemble parts of the fetal brain [00:00:10], [00:00:12], [00:00:15], [00:04:55], [00:04:57], [00:05:01], [00:05:19], [00:05:22], [00:05:27], [00:05:32].
Sustaining Organoid Life
Organoids are grown in an incubator under precise conditions of temperature (37 degrees Celsius like the human body) and carbon dioxide concentration [00:04:39], [00:04:42], [00:04:45], [00:06:45], [00:06:48], [00:06:51], [00:06:53], [00:06:56]. They are nourished with a special culture medium containing nutrients [00:05:51], [00:05:55], [00:05:57], [00:06:01]. A flow system with tubes and a pump ensures the growing medium continuously flows under the organoid, aiding survival [00:06:23], [00:06:25], [00:06:28], [00:06:31], [00:06:34]. Some organoids are kept on an orbital shaker to facilitate nutrient and oxygen entry [00:05:35], [00:05:38], [00:05:42]. The most challenging aspect has been keeping them alive; initially, they would die within hours, but now they can be sustained for weeks, and even almost 3 years [00:00:36], [00:00:39], [00:07:06], [00:14:05], [00:14:07], [00:14:09], [00:14:11], [00:14:14], [00:14:16].
Neural Activity and Communication
Organoids are connected to a neural platform by placing them on a multi-electrode array (MEA) [00:07:14], [00:07:17], [00:07:20], [00:07:22]. This allows for recording their activity [00:07:25], [00:07:28]. The MEA helps position the organoid precisely and reduces system noise [00:08:48], [00:08:50], [00:08:53]. The moment neuronal activity was successfully recorded was “amazing” [00:00:32], [00:00:35], [00:16:21], [00:16:24].
The Butterfly Experiment
The butterfly experiment demonstrates real-time interaction with brain organoids for browser-based users [00:11:16], [00:11:18], [00:11:20], [00:11:22], [00:11:25], [00:11:28].
- Concept: A virtual butterfly moves in 3D, and its flight direction is controlled by interacting with the organoids [00:11:44], [00:11:46], [00:11:48], [00:11:51], [00:11:55].
- Stimulation: When the butterfly “sees” light (represented by blue dots), stimulation is sent to the organoids [00:11:58], [00:12:01], [00:12:04], [00:12:08].
- Response: If the organoid responds to the stimulation, the butterfly flies straight towards the light; if not, it moves randomly [00:12:10], [00:12:13], [00:12:17], [00:12:20].
- Neural Burst: A response appears as a “large wave” or “burst” of activity, indicating many neurons communicating and transmitting information [00:00:17], [00:00:19], [00:12:28], [00:12:30], [00:12:33], [00:12:36].
- Communication: This system demonstrates successful communication established with the organoids [00:12:39], [00:12:43], [00:12:47], [00:12:49], [00:12:51], [00:12:54].
Information Processing and Learning
To get neurons to process information and enforce behavior, researchers use strategies such as rewarding organoids with dopamine when they perform a desired action [00:13:03], [00:13:07], [00:13:09], [00:13:12], [00:13:15], [00:13:19], [00:13:22], [00:13:35], [00:13:38], [00:13:40]. Observing the neural tissue response to dopamine, with a wave of activity typical of dopamine-induced stimulation, was a significant success [00:16:36], [00:16:39], [00:16:41], [00:16:43], [00:16:46], [00:16:48]. This is considered “learning” in the context of biocomputation [00:13:22].
Energy Efficiency
The primary motivation for developing biological processors was the unsustainable energy consumption of artificial neural networks [00:09:12], [00:09:14], [00:09:16], [00:09:19], [00:09:21], [00:09:34], [00:09:39].
- Contrast with AI: Simulations of 100 neurons in artificial neural networks can consume several kilowatts of power [00:09:50], [00:09:53], [00:09:55], [00:09:58], [00:10:01], [00:10:04]. In contrast, the human brain, with 86 billion neurons, requires only 20 watts [00:10:07], [00:10:11], [00:10:16], [00:10:18], [00:10:22].
- Efficiency: Biological processors are by far the most energy-efficient method, with a difference described as a millionth [00:00:23], [00:00:25], [00:00:28], [00:00:30].
- Implication: This efficiency drastically reduces the carbon footprint of AI development [00:17:31], [00:17:33], [00:17:35].
The Future of Computing
Biocomputing is seen as the future of data processing, particularly for artificial intelligence calculations [00:16:56], [00:16:58], [00:17:06], [00:17:10]. Just as quantum computers are specialized, biocomputing can be used for specific computational types, where AI fits perfectly because it is based on neuron simulations [00:17:13], [00:17:15], [00:17:18], [00:17:21], [00:17:22], [00:17:24], [00:17:26]. This project has attracted dozens of universities and has the potential to transform AI development [00:17:29], [00:17:31], [00:17:33].
Ethical Considerations
Final Spark acknowledges the ethical concerns surrounding the use of living neurons for computational purposes [00:00:44], [00:01:19], [00:14:19], [00:14:46], [00:14:49], [00:14:52], [00:14:54]. They have established contacts with universities and ethics experts, attending conferences to introduce ethicists to their work [00:14:57], [00:14:59], [00:15:02], [00:15:05], [00:15:09], [00:15:12], [00:15:13], [00:15:17].
Why Human Cells?
While rat cells could potentially work for computations, human cells are preferred for development of biological processors [00:15:32], [00:15:36], [00:15:39], [00:15:41], [00:15:47]. This choice is driven by the potential for future therapeutic applications that could directly benefit people, rather than rats [00:15:49], [00:15:51], [00:15:53], [00:15:56], [00:15:59], [00:16:04], [00:16:07], [00:16:09].