Python Implementation:

class PaymentChannel:
    def __init__(self, sender, receiver, balance):
        self.sender = sender
        self.receiver = receiver
        self.balance = balance

    def update_balance(self, amount):
        self.balance += amount

# Example usage:
sender_address = "sender_address"
receiver_address = "receiver_address"
initial_balance = 10

# Create a payment channel
channel = PaymentChannel(sender_address, receiver_address, initial_balance)

# Update the balance
channel.update_balance(-5)  # Deduct 5 from sender's balance
channel.update_balance(5)   # Add 5 to receiver's balance

# Print updated balance
print(f"Sender balance: {channel.sender} BTC")
print(f"Receiver balance: {channel.receiver} BTC")