The **GABRA4** gene encodes the alpha-4 subunit of the gamma-aminobutyric acid (GABA) receptor, which plays a critical role in inhibitory neurotransmission in the mammalian central nervous system. Here, I will expand upon your request regarding the GABRA4 gene.

### 1. Associated Genes
In addition to **GABRB1**, which was mentioned in the summary you provided, other genes associated with GABRA4 include:
- **GABRL1**: Gamma-aminobutyric acid receptor, subunit pi.
- **GABRA1**: Gamma-aminobutyric acid receptor subunit alpha-1.
- **GABRA2**: Gamma-aminobutyric acid receptor subunit alpha-2.
- **GABRB2**: Gamma-aminobutyric acid receptor subunit beta-2.
- **GABRG2**: Gamma-aminobutyric acid receptor subunit gamma-2.

These genes encode various subunits of GABA receptors, contributing to the diversity of GABA receptor complexes and their functional properties.

### 2. Aging and Age-Related Diseases
The GABRA4 gene and its protein product have been implicated in several neurodevelopmental and neuropsychiatric disorders, including autism spectrum disorder (ASD). While specific studies focusing on the role of GABRA4 in aging and age-related diseases are limited, the following points can be noted:
- Alterations in GABAergic signaling can lead to a disruption in neuronal plasticity, which is crucial for age-related cognitive decline.
- Dysregulation of GABA A receptor subunits, including GABRA4, has been associated with neurodegenerative diseases such as Alzheimer's disease and Parkinson’s disease, where GABAergic neurons are affected.
- Changes in the expression patterns of GABA receptor subunits have been observed in aging models, implicating their potential role in age-related neurophysiological changes.

### 3. Drug Interactions
The GABRA4 gene product interacts with several drug classes, particularly those that modulate GABAergic signaling. Notable examples include:
- **Benzodiazepines**: Benzodiazepines, such as diazepam and lorazepam, enhance the effect of GABA at the GABA A receptor, including those containing the alpha-4 subunit.
- **Barbiturates**: These drugs also potentiate GABA-A receptor activity but through a different mechanism than benzodiazepines.
- **Non-benzodiazepine GABA modulators**: Drugs like zolpidem target GABA A receptors and may involve subunits like GABRA4.
- **Antiepileptic drugs**: Some drugs used to treat epilepsy, such as valproate, may interact with GABA receptor signaling.

### 4. Pathways and Biological Processes
The GABRA4 gene is involved in several important biological processes and signaling pathways:
- **GABAergic signaling**: The primary biological process associated with GABRA4 is inhibitory neurotransmission via GABA receptors. This is crucial for maintaining neuronal excitability and balance in the CNS.
- **Neurotransmitter receptor activity**: GABRA4 contributes to the function of ligand-gated ion channels, facilitating chloride ion flux and mediating synaptic inhibition.
- **Regulation of synaptic transmission**: The gene is implicated in the modulation of synaptic plasticity and may influence learning and memory.
- **Involvement in pathways related to neuropsychiatric disorders**: GABRA4 is part of several neurodevelopmental pathways, particularly influencing vulnerability to autism and mood disorders.

In summary, the GABRA4 gene plays a significant role in GABA receptor activity, impacting both neuronal signaling and neurodevelopmental processes. Its interactions with various pharmacological agents illustrate its importance in therapeutic contexts, especially in neuropsychiatric conditions. Further research into GABRA4 could provide deeper insights into its role in aging and neurological diseases.