I forgot to. They are now called conversations. As alpink notes click on the avatar name beside a (thread) discussion post to start a conversation with someone. You can also click on the profile picture in the upper right corner of the screen.
If you have had conversation started to you it will be listed there either both or in the alerts or as a conversation depending on your account settings.
If you click on conversation you will see any new ones and all the previous ones.
The alerts will show you discussion responses, likes, awards and membership milestones as the occur.
In your account settings you can set these and other various alerts to be sent to you as above, by email or a push notifications as they are made by others and the system.
Great colour & stance on the Lunatic dragster!!
RM, you made my day with: "...having to re-learn.." & " can't even find the PM's ", can't stop LOL since I made the same comments on my thread! Great minds think alike!!! ... RL