Neuroplasticity tools for drug discovery

Historically, quantification of compound effects on neuroplasticity has been challenging due to low throughput and assay variability. We have addressed that by establishing highly reproducible and validated high-throughput assays to measure structural and functional neuroplasticity in vitro.

Loss of synapses – good or bad?

Although it is often thought that loss of neurons or synapses is harmful, elimination of connections that do not mediate useful information is necessary for establishing an optimal signal-to-noise ratio within the nervous system and the connections are strengthened, maintained, or eliminated in a use-dependent manner.

Diseases related to neuroplasticity involve abnormalities or dysfunctions in the brain's ability to adapt and reorganize its connections. Examples of diseases where neuroplasticity is a key mechanism are neuropsychiatric disorders such as depression and schizophrenia¹^, ². Other examples are epilepsy and neurodegenerative diseases such as Alzheimer's disease (AD). In AD, accumulation of beta-amyloid plaques and tau tangles disrupts neuroplasticity, which in turn leads to cognitive decline and memory loss.

Considering neuropsychiatric disorders, the incidence has increased dramatically during the past two decades and there is an urgent need for continued Drug Discovery to identify novel targets and molecules for neuropsychiatric diseases that will be safer and more efficacious than currently prescribed medicines. To aid our Clients’ drug discovery efforts, we have assembled a suite of extensively validated native in vitro models in the NP service module.

susanne lardell
external collaborations manager

We are creating novel assays for modelling neuroplasticity

“Neuroplasticity has a crucial role in early brain development, but also for the brain’s ability to adapt to changes throughout life. With our service module, we have established high-quality neuroplasticity in vitro models, which our Clients are using to develop innovative treatments for neuropsychiatric and neurodegenerative diseases.”

Validity

The module consists of high content imaging and optical electrophysiology assays where effects on key features can be quantified on neurite and network level – as validated by a wide set of clinically relevant compounds for neuropsychiatry and epilepsy.

Efficiency

To ensure high reproducibility and precision, we work exclusively in 384- and 96-well formats. With the right study design this enables both sufficient capacity to support medium throughput screening campaigns and provides statistically robust results.

Flexibility

The models, taking into account both anatomical and functional aspects, can be used stand-alone or in combination for your target and lead discovery projects. The broader data package facilitates translation both to in vivo and human testing in drug development.

Quality

We are experienced in tackling the inherent variability that comes with using complex neuronal preparations. Applying a rigorous process and QC-criteria, we generate highly reproducible results between repeat measurements and over extended time.

The opportunity for drug discovery

There is a clear connection between neuroplasticity and existing as well as emerging drugs for neuropsychiatric diseases. This provides a handle for continued drug discovery to identify novel targets and molecules that affect neuroplasticity in vitro.

Improper neuritogenesis or inhibition of neurite outgrowth underlie a variety of neurodevelopmental and neuropsychiatric disorders. Following neuritogenesis, synaptic molecules are assembled at pre- and post-synaptic sites that are in turn aligned and connected to support synaptic function. Many of the existing drugs for these conditions have polypharmacological profiles. This points to the importance of using complex models. We took this into account when we created the NP service module.

In the module, we have assembled a suite of extensively validated native in vitro models that cover neurobiological events from neuritogenesis³ to synaptogenesis⁷ and synaptic function⁴^,⁵. In the module, loss of neuronal structures can be induced to, for example, study genetic or small molecule regulation of neuroplasticity. Since the included assays have high capacity, the analysis is performed on many cells per well and from many wells per condition to provide statistically robust readouts. The assays can be applied for screening of novel drugs, for elucidating mechanism of action and for Target Discovery.

The neuritogenesis assay

The neuritogenesis assay is an HCA assay based on rodent cortex that is capable of quantifying compound effects on complex, single cell parameters for neurites, such as number of branch points and length of individual neurites, in a reproducible manner³. Besides being valuable for large-scale screening, the inherent high capacity and reproducibility of the assay also enables evaluation of complex pharmacological interactions.

The synaptogenesis assay

Mutations in genes encoding synaptic proteins are frequently associated with abnormal synaptogenesis. To enable detailed studies on synapse generation and synapse loss, we are working with HCA in high-density rodent cortical cultures. By labeling pre- and postsynaptic structures, we quantify drug-induced changes in colocalization of the pre- and postsynaptic proteins⁷. Further, the neuritogenesis and synaptogenesis assays can be applied in parallel to provide a better understanding of how targets and molecules are affecting various aspects of neuroplasticity.

Assays for axonal transport and growth dynamics

Defects in axonal transport and growth dynamics have been reported as common features in different neurodegenerative diseases. By physically isolating axons from the soma and dendrites, we can study axonal transport as well as for example polymerization/depolymerization of microtubule and how this can be modulated using our proprietary high-capacity microfluidic co-culture plate⁶.

The synaptic function assay

Two key changes that occur in neurological diseases are alterations in neuronal excitability and synaptic signalling. In the synaptic function assay, we use cortical cultures where the neurons become synaptically connected as cultures mature. Effects on population level, caused either by genetic modulation of targets of interest or by the addition of test compounds, are quantified as changes in neuronal calcium influx in a high-capacity manner. The assay is validated with molecules having a wide range of mechanisms of action, making it suitable both for target-based approaches and phenotypic screening⁴, ⁵.

paul karila
CBO

Your partner for neuroplasticity research and drug discovery

“Building on our deep experience in high-capacity screening for Target and Lead Discovery, we have generated a suite of high-quality neuroplasticity assays. They can of course be used in isolation, but often we profile compounds across all assays in the module as this adds significant value to our Clients’ drug discovery projects.”

Case studies

The assays in the module, taking into account both anatomical and functional aspects, are suitable for Lead Identification, Lead Optimization, mechanism of action studies, as well as for Target Discovery to identify novel targets.

Download Case Study (PDF)

References

1. Park H, Poo MM. Neurotrophin regulation of neural circuit development and function. Nat Rev Neurosci. 2013 Jan;14(1):7-23. doi: 10.1038/nrn3379. PMID: 23254191.

2. Lullau APM, Haga EMW, Ronold EH, Dwyer GE. Antidepressant mechanisms of ketamine: a review of actions with relevance to treatment-resistance and neuroprogression. Front Neurosci. 2023 Aug 8;17: 1223145. doi: 10.3389/fnins.2023.1223145. PMID: 37614344; PMCID: PMC10442706.

3. S. ENGEL1, L. MOLL2,4, S. M. LARDELL3, J. PIHL5, P. KARILA5, M. CHYTIL1, R. AGRAWAL1, N. A. POWELL1;
1 Delix Therapeut., Concord, MA; 2 Cellectricon, Stockholm, Sweden; 3 Cellectricon, Mölndal, Sweden; 4 Dept. of Physiol. and Pharmacol., Karolinska Institutet, Stockholm, Sweden; 5 Cellectricon AB, Mölndal, Sweden. Development of a high content cortical neuroplasticity assay for the assessment of structural plasticity of psychedelics. Program No. 694.11. 2022 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2022. Online.

4. R. NEFF1, C. LINDWALLBLOM2, Å. JÄGERVALL2, B. BALANA1, M. KARLSSON2, P. KARILA2, T. LOVENBERG1;
1 Neurosci. Drug Discovery, Janssen Res. and Develop., San Diego, CA; 2 Cellectricon AB, Mölndal, Sweden. Development of a moderate throughput assay to detect novel modulators of synaptic efficacy in neuronal cultures. Program No. 209.10. 2015 Neuroscience Meeting Planner. Chicago, IL: Society for Neuroscience, 2015. Online.

5. SATIR TM, AGHOLME L, KARLSSON A, KARLSSON M, KARILA P, ILLES S, BERGSTRÖM P, ZETTERBERG H. Partial reduction of amyloid β production by β-secretase inhibitors does not decrease synaptic transmission. Alzheimers Res Ther. 2020 May 26;12(1):63. doi: 10.1186/s13195-020-00635-0. PMID: 32456694; PMCID: PMC7251689.

6. L. STRID ORRHULT1, N. ARBEZ2, P. DELAGRANGE3, J. PIHL1, M. KARLSSON1;
1 Cellectricon AB, Cellectricon, Mölndal, Sweden; 2 Cell. Sci. Dept., 3 Neurol. and Inflammation Therapeut. Area, Inst. de Recherches Servier, Croissy sur Seine, France. Development of an assay for compounds modulating tyrosination and de-tyrosination in mouse cortical cultures using microfluidic co-culture plates. Program No. 085.10. 2022 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2022. Online.

7. S. ENGEL1, S. LARDELL2, R. AGRAWAL1, A. MUNGENAST1, M. CHYTIL1, P. KARILA2;
1Delix Therapeut., Bedford, MA; 2Cellectricon AB, Mölndal, Sweden. Development of high content in vitro assays for the assessment of structural neuroplasticity. Program No. PSTR069.05. 2023 Neuroscience Meeting Planner. Washington, D.C.: Society for Neuroscience, 2023. Online.